From 2761548a2c4f8c68e3ec61249909f309abae8a91 Mon Sep 17 00:00:00 2001
From: Harriet Brown <harriet.brown@stfc.ac.uk>
Date: Fri, 6 Mar 2020 10:25:55 +0000
Subject: [PATCH] Replace header guards in Kernel with pragma once

This commit replaces all header guards in Kernel with #pragma once
---
 Framework/Kernel/inc/MantidKernel/ANN/ANN.h                 | 5 +----
 Framework/Kernel/inc/MantidKernel/ANN/ANNperf.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/ANN/ANNx.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/ArrayBoundedValidator.h   | 5 +----
 Framework/Kernel/inc/MantidKernel/ArrayLengthValidator.h    | 5 +----
 .../Kernel/inc/MantidKernel/ArrayOrderedPairsValidator.h    | 5 +----
 Framework/Kernel/inc/MantidKernel/ArrayProperty.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/Atom.h                    | 5 +----
 Framework/Kernel/inc/MantidKernel/BinFinder.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/BinaryFile.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/BinaryStreamReader.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/BinaryStreamWriter.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/BoundedValidator.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/CPUTimer.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/Cache.h                   | 5 +----
 Framework/Kernel/inc/MantidKernel/CaseInsensitiveMap.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/CatalogInfo.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/Chainable.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/ChainableFactory.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/ChecksumHelper.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/CompositeValidator.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/ComputeResourceInfo.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/ConfigObserver.h          | 6 ++----
 Framework/Kernel/inc/MantidKernel/ConfigPropertyObserver.h  | 6 ++----
 Framework/Kernel/inc/MantidKernel/ConfigService.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/DataItem.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/DataService.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/DateAndTime.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/DateAndTimeHelpers.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/DateTimeValidator.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/DateValidator.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/DeltaEMode.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/Diffraction.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/DirectoryValidator.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/DiskBuffer.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/DllConfig.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/DllOpen.h                 | 5 +----
 Framework/Kernel/inc/MantidKernel/DocumentationHeader.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/DynamicFactory.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/EigenConversionHelpers.h  | 5 +----
 Framework/Kernel/inc/MantidKernel/EmptyValues.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/EnabledWhenProperty.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/EnvironmentHistory.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/EqualBinsChecker.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/ErrorReporter.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/Exception.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/FacilityInfo.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/Fast_Exponential.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/FileDescriptor.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/FileValidator.h           | 5 +----
 .../Kernel/inc/MantidKernel/FilteredTimeSeriesProperty.h    | 5 +----
 Framework/Kernel/inc/MantidKernel/FloatingPointComparison.h | 5 +----
 Framework/Kernel/inc/MantidKernel/FreeBlock.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/FunctionTask.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/Glob.h                    | 5 +----
 Framework/Kernel/inc/MantidKernel/ICatalogInfo.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/INode.h                   | 5 +----
 Framework/Kernel/inc/MantidKernel/IPropertyManager.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/IPropertySettings.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/ISaveable.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/ITimeSeriesProperty.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/IValidator.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/IndexSet.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/Instantiator.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/InstrumentInfo.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/InternetHelper.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/Interpolation.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/InvisibleProperty.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/LibraryManager.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/LibraryWrapper.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/ListValidator.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/LiveListenerInfo.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/LogFilter.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/LogParser.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/Logger.h                  | 5 +----
 Framework/Kernel/inc/MantidKernel/MDAxisValidator.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/MDUnit.h                  | 5 +----
 Framework/Kernel/inc/MantidKernel/MDUnitFactory.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/MRUList.h                 | 5 +----
 Framework/Kernel/inc/MantidKernel/MagneticIon.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/MandatoryValidator.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/MantidVersion.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/MaskedProperty.h          | 6 ++----
 Framework/Kernel/inc/MantidKernel/Material.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/MaterialBuilder.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/MaterialXMLParser.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/Math/ChebyshevPolyFit.h   | 5 +----
 .../MantidKernel/Math/Distributions/ChebyshevPolynomial.h   | 5 +----
 .../inc/MantidKernel/Math/Distributions/ChebyshevSeries.h   | 5 +----
 .../inc/MantidKernel/Math/Optimization/SLSQPMinimizer.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/Matrix.h                  | 6 ++----
 Framework/Kernel/inc/MantidKernel/MatrixProperty.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/Memory.h                  | 5 +----
 Framework/Kernel/inc/MantidKernel/MersenneTwister.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/MultiFileNameParser.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/MultiFileValidator.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/MultiThreaded.h           | 5 +----
 .../Kernel/inc/MantidKernel/NDPseudoRandomNumberGenerator.h | 5 +----
 Framework/Kernel/inc/MantidKernel/NDRandomNumberGenerator.h | 5 +----
 Framework/Kernel/inc/MantidKernel/NearestNeighbours.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/NetworkProxy.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/NeutronAtom.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/NexusDescriptor.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/NullValidator.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/OptionalBool.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/ParaViewVersion.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/PhysicalConstants.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/PrecompiledHeader.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/ProgressBase.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/Property.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyHelper.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyHistory.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyManager.h         | 5 +----
 .../Kernel/inc/MantidKernel/PropertyManagerDataService.h    | 6 ++----
 Framework/Kernel/inc/MantidKernel/PropertyManagerOwner.h    | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyManagerProperty.h | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyManager_fwd.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyNexus.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyWithValue.h       | 5 +----
 Framework/Kernel/inc/MantidKernel/PropertyWithValueJSON.h   | 5 +----
 Framework/Kernel/inc/MantidKernel/ProxyInfo.h               | 5 +----
 .../Kernel/inc/MantidKernel/PseudoRandomNumberGenerator.h   | 5 +----
 .../Kernel/inc/MantidKernel/QuasiRandomNumberSequence.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/Quat.h                    | 5 +----
 Framework/Kernel/inc/MantidKernel/ReadLock.h                | 5 +----
 Framework/Kernel/inc/MantidKernel/RebinParamsValidator.h    | 5 +----
 Framework/Kernel/inc/MantidKernel/RegexStrings.h            | 6 ++----
 Framework/Kernel/inc/MantidKernel/RegistrationHelper.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/RemoteJobManager.h        | 5 +----
 Framework/Kernel/inc/MantidKernel/SimpleJSON.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/SingletonHolder.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/SobolSequence.h           | 5 +----
 Framework/Kernel/inc/MantidKernel/SpecialCoordinateSystem.h | 5 +----
 Framework/Kernel/inc/MantidKernel/StartsWithValidator.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/Statistics.h              | 6 ++----
 Framework/Kernel/inc/MantidKernel/StdoutChannel.h           | 6 ++----
 Framework/Kernel/inc/MantidKernel/StringContainsValidator.h | 5 +----
 Framework/Kernel/inc/MantidKernel/StringTokenizer.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/Strings.h                 | 5 +----
 Framework/Kernel/inc/MantidKernel/System.h                  | 5 +----
 Framework/Kernel/inc/MantidKernel/Task.h                    | 5 +----
 Framework/Kernel/inc/MantidKernel/TestChannel.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/ThreadPool.h              | 5 +----
 Framework/Kernel/inc/MantidKernel/ThreadPoolRunnable.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/ThreadSafeLogStream.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/ThreadScheduler.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h  | 5 +----
 Framework/Kernel/inc/MantidKernel/TimeSeriesProperty.h      | 5 +----
 Framework/Kernel/inc/MantidKernel/TimeSplitter.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/Timer.h                   | 5 +----
 Framework/Kernel/inc/MantidKernel/Tolerance.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/TopicInfo.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/TypedValidator.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/Unit.h                    | 5 +----
 Framework/Kernel/inc/MantidKernel/UnitConversion.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/UnitFactory.h             | 5 +----
 Framework/Kernel/inc/MantidKernel/UnitLabel.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/UnitLabelTypes.h          | 5 +----
 Framework/Kernel/inc/MantidKernel/UsageService.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/UserCatalogInfo.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/UserStringParser.h        | 6 ++----
 Framework/Kernel/inc/MantidKernel/Utils.h                   | 5 +----
 Framework/Kernel/inc/MantidKernel/V2D.h                     | 5 +----
 Framework/Kernel/inc/MantidKernel/V3D.h                     | 5 +----
 Framework/Kernel/inc/MantidKernel/VMD.h                     | 5 +----
 Framework/Kernel/inc/MantidKernel/VectorHelper.h            | 5 +----
 Framework/Kernel/inc/MantidKernel/VisibleWhenProperty.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/WarningSuppressions.h     | 5 +----
 Framework/Kernel/inc/MantidKernel/WriteLock.h               | 5 +----
 Framework/Kernel/inc/MantidKernel/XMLInstantiator.h         | 5 +----
 Framework/Kernel/inc/MantidKernel/cow_ptr.h                 | 5 +----
 Framework/Kernel/inc/MantidKernel/make_cow.h                | 6 ++----
 Framework/Kernel/inc/MantidKernel/normal_distribution.h     | 5 +----
 .../Kernel/inc/MantidKernel/uniform_int_distribution.h      | 5 +----
 Framework/Kernel/src/ANN/bd_tree.h                          | 5 +----
 Framework/Kernel/src/ANN/kd_fix_rad_search.h                | 5 +----
 Framework/Kernel/src/ANN/kd_pr_search.h                     | 5 +----
 Framework/Kernel/src/ANN/kd_search.h                        | 5 +----
 Framework/Kernel/src/ANN/kd_split.h                         | 5 +----
 Framework/Kernel/src/ANN/kd_tree.h                          | 5 +----
 Framework/Kernel/src/ANN/kd_util.h                          | 5 +----
 Framework/Kernel/src/ANN/pr_queue.h                         | 5 +----
 Framework/Kernel/src/ANN/pr_queue_k.h                       | 5 +----
 Framework/Kernel/test/ArrayBoundedValidatorTest.h           | 5 +----
 Framework/Kernel/test/ArrayLengthValidatorTest.h            | 5 +----
 Framework/Kernel/test/ArrayOrderedPairsValidatorTest.h      | 5 +----
 Framework/Kernel/test/ArrayPropertyTest.h                   | 5 +----
 Framework/Kernel/test/AtomTest.h                            | 5 +----
 Framework/Kernel/test/BinFinderTest.h                       | 5 +----
 Framework/Kernel/test/BinaryFileTest.h                      | 5 +----
 Framework/Kernel/test/BinaryStreamReaderTest.h              | 5 +----
 Framework/Kernel/test/BinaryStreamWriterTest.h              | 6 ++----
 Framework/Kernel/test/BoundedValidatorTest.h                | 5 +----
 Framework/Kernel/test/CPUTimerTest.h                        | 5 +----
 Framework/Kernel/test/CacheTest.h                           | 5 +----
 Framework/Kernel/test/CatalogInfoTest.h                     | 5 +----
 Framework/Kernel/test/ChebyshevPolyFitTest.h                | 5 +----
 Framework/Kernel/test/ChebyshevPolynomialTest.h             | 5 +----
 Framework/Kernel/test/ChebyshevSeriesTest.h                 | 5 +----
 Framework/Kernel/test/ChecksumHelperTest.h                  | 5 +----
 Framework/Kernel/test/CompositeValidatorTest.h              | 5 +----
 Framework/Kernel/test/ComputeResourceInfoTest.h             | 5 +----
 Framework/Kernel/test/ConfigObserverTest.h                  | 6 ++----
 Framework/Kernel/test/ConfigPropertyObserverTest.h          | 6 ++----
 Framework/Kernel/test/ConfigServiceTest.h                   | 5 +----
 Framework/Kernel/test/CowPtrTest.h                          | 5 +----
 Framework/Kernel/test/DataServiceTest.h                     | 5 +----
 Framework/Kernel/test/DateAndTimeHelpersTest.h              | 5 +----
 Framework/Kernel/test/DateAndTimeTest.h                     | 5 +----
 Framework/Kernel/test/DateTimeValidatorTest.h               | 5 +----
 Framework/Kernel/test/DateValidatorTest.h                   | 5 +----
 Framework/Kernel/test/DeltaEModeTest.h                      | 5 +----
 Framework/Kernel/test/DiffractionTest.h                     | 5 +----
 Framework/Kernel/test/DirectoryValidatorTest.h              | 5 +----
 Framework/Kernel/test/DiskBufferISaveableTest.h             | 5 +----
 Framework/Kernel/test/DiskBufferTest.h                      | 5 +----
 Framework/Kernel/test/DllOpenTest.h                         | 5 +----
 Framework/Kernel/test/DynamicFactoryTest.h                  | 5 +----
 Framework/Kernel/test/EigenConversionHelpersTest.h          | 5 +----
 Framework/Kernel/test/EnabledWhenPropertyTest.h             | 5 +----
 Framework/Kernel/test/EnvironmentHistoryTest.h              | 5 +----
 Framework/Kernel/test/EqualBinsCheckerTest.h                | 5 +----
 Framework/Kernel/test/ErrorReporterTest.h                   | 5 +----
 Framework/Kernel/test/FacilitiesTest.h                      | 5 +----
 Framework/Kernel/test/FileDescriptorTest.h                  | 5 +----
 Framework/Kernel/test/FileValidatorTest.h                   | 5 +----
 Framework/Kernel/test/FilteredTimeSeriesPropertyTest.h      | 5 +----
 Framework/Kernel/test/FloatingPointComparisonTest.h         | 5 +----
 Framework/Kernel/test/FreeBlockTest.h                       | 5 +----
 Framework/Kernel/test/FunctionTaskTest.h                    | 5 +----
 Framework/Kernel/test/GlobTest.h                            | 5 +----
 Framework/Kernel/test/IPropertySettingsTest.h               | 5 +----
 Framework/Kernel/test/ISaveableTest.h                       | 5 +----
 Framework/Kernel/test/IValidatorTest.h                      | 5 +----
 Framework/Kernel/test/IndexSetTest.h                        | 5 +----
 Framework/Kernel/test/InstrumentInfoTest.h                  | 6 ++----
 Framework/Kernel/test/InternetHelperTest.h                  | 5 +----
 Framework/Kernel/test/InterpolationTest.h                   | 5 +----
 Framework/Kernel/test/InvisiblePropertyTest.h               | 5 +----
 Framework/Kernel/test/ListValidatorTest.h                   | 5 +----
 Framework/Kernel/test/LiveListenerInfoTest.h                | 5 +----
 Framework/Kernel/test/LogFilterTest.h                       | 5 +----
 Framework/Kernel/test/LogParserTest.h                       | 5 +----
 Framework/Kernel/test/LoggerTest.h                          | 5 +----
 Framework/Kernel/test/MDAxisValidatorTest.h                 | 5 +----
 Framework/Kernel/test/MDUnitFactoryTest.h                   | 5 +----
 Framework/Kernel/test/MDUnitTest.h                          | 5 +----
 Framework/Kernel/test/MRUListTest.h                         | 5 +----
 Framework/Kernel/test/MagneticIonTest.h                     | 5 +----
 Framework/Kernel/test/MakeCowTest.h                         | 5 +----
 Framework/Kernel/test/MandatoryValidatorTest.h              | 5 +----
 Framework/Kernel/test/MaskedPropertyTest.h                  | 5 +----
 Framework/Kernel/test/MaterialBuilderTest.h                 | 5 +----
 Framework/Kernel/test/MaterialTest.h                        | 6 ++----
 Framework/Kernel/test/MaterialXMLParserTest.h               | 5 +----
 Framework/Kernel/test/MatrixPropertyTest.h                  | 5 +----
 Framework/Kernel/test/MatrixTest.h                          | 5 +----
 Framework/Kernel/test/MemoryTest.h                          | 5 +----
 Framework/Kernel/test/MersenneTwisterTest.h                 | 5 +----
 Framework/Kernel/test/MultiFileNameParserTest.h             | 5 +----
 Framework/Kernel/test/MultiFileValidatorTest.h              | 5 +----
 Framework/Kernel/test/MutexTest.h                           | 5 +----
 Framework/Kernel/test/NDPseudoRandomNumberGeneratorTest.h   | 5 +----
 Framework/Kernel/test/NDRandomNumberGeneratorTest.h         | 5 +----
 Framework/Kernel/test/NearestNeighboursTest.h               | 5 +----
 Framework/Kernel/test/NeutronAtomTest.h                     | 5 +----
 Framework/Kernel/test/NexusDescriptorTest.h                 | 5 +----
 Framework/Kernel/test/NullValidatorTest.h                   | 5 +----
 Framework/Kernel/test/OptionalBoolTest.h                    | 5 +----
 Framework/Kernel/test/PrecompiledHeader.h                   | 5 +----
 Framework/Kernel/test/ProgressBaseTest.h                    | 5 +----
 Framework/Kernel/test/PropertyHistoryTest.h                 | 5 +----
 Framework/Kernel/test/PropertyManagerDataServiceTest.h      | 5 +----
 Framework/Kernel/test/PropertyManagerPropertyTest.h         | 5 +----
 Framework/Kernel/test/PropertyManagerTest.h                 | 5 +----
 Framework/Kernel/test/PropertyNexusTest.h                   | 5 +----
 Framework/Kernel/test/PropertyTest.h                        | 5 +----
 Framework/Kernel/test/PropertyWithValueJSONTest.h           | 5 +----
 Framework/Kernel/test/PropertyWithValueTest.h               | 5 +----
 Framework/Kernel/test/ProxyInfoTest.h                       | 5 +----
 Framework/Kernel/test/QuatTest.h                            | 5 +----
 Framework/Kernel/test/ReadLockTest.h                        | 5 +----
 Framework/Kernel/test/RebinHistogramTest.h                  | 5 +----
 Framework/Kernel/test/RebinParamsValidatorTest.h            | 5 +----
 Framework/Kernel/test/RegexStringsTest.h                    | 5 +----
 Framework/Kernel/test/SLSQPMinimizerTest.h                  | 5 +----
 Framework/Kernel/test/ShrinkToFitTest.h                     | 5 +----
 Framework/Kernel/test/SimpleJSONTest.h                      | 5 +----
 Framework/Kernel/test/SobolSequenceTest.h                   | 5 +----
 Framework/Kernel/test/SpecialCoordinateSystemTest.h         | 5 +----
 Framework/Kernel/test/StartsWithValidatorTest.h             | 5 +----
 Framework/Kernel/test/StatisticsTest.h                      | 5 +----
 Framework/Kernel/test/StdoutChannelTest.h                   | 5 +----
 Framework/Kernel/test/StringContainsValidatorTest.h         | 5 +----
 Framework/Kernel/test/StringTokenizerTest.h                 | 5 +----
 Framework/Kernel/test/StringsTest.h                         | 5 +----
 Framework/Kernel/test/TaskTest.h                            | 5 +----
 Framework/Kernel/test/ThreadPoolRunnableTest.h              | 5 +----
 Framework/Kernel/test/ThreadPoolTest.h                      | 5 +----
 Framework/Kernel/test/ThreadSchedulerMutexesTest.h          | 5 +----
 Framework/Kernel/test/ThreadSchedulerTest.h                 | 5 +----
 Framework/Kernel/test/TimeSeriesPropertyTest.h              | 5 +----
 Framework/Kernel/test/TimeSplitterTest.h                    | 5 +----
 Framework/Kernel/test/TimerTest.h                           | 5 +----
 Framework/Kernel/test/TopicInfoTest.h                       | 5 +----
 Framework/Kernel/test/TypedValidatorTest.h                  | 5 +----
 Framework/Kernel/test/UnitConversionTest.h                  | 5 +----
 Framework/Kernel/test/UnitFactoryTest.h                     | 5 +----
 Framework/Kernel/test/UnitLabelTest.h                       | 5 +----
 Framework/Kernel/test/UnitTest.h                            | 5 +----
 Framework/Kernel/test/UsageServiceTest.h                    | 5 +----
 Framework/Kernel/test/UserCatalogInfoTest.h                 | 5 +----
 Framework/Kernel/test/UserStringParserTest.h                | 5 +----
 Framework/Kernel/test/UtilsTest.h                           | 5 +----
 Framework/Kernel/test/V2DTest.h                             | 5 +----
 Framework/Kernel/test/V3DTest.h                             | 5 +----
 Framework/Kernel/test/VMDTest.h                             | 5 +----
 Framework/Kernel/test/VectorHelperTest.h                    | 5 +----
 Framework/Kernel/test/VisibleWhenPropertyTest.h             | 5 +----
 Framework/Kernel/test/WriteLockTest.h                       | 5 +----
 320 files changed, 335 insertions(+), 1280 deletions(-)

diff --git a/Framework/Kernel/inc/MantidKernel/ANN/ANN.h b/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
index 28aa949db84..8ae8fe654c1 100644
--- a/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
+++ b/Framework/Kernel/inc/MantidKernel/ANN/ANN.h
@@ -66,8 +66,7 @@
 //				1994, 573-582.
 //----------------------------------------------------------------------
 
-#ifndef ANN_H
-#define ANN_H
+#pragma once
 
 // M. Gigg: Added the next two pragmas to supress the warnings regarding
 // unused parameters since this is a third party package
@@ -901,5 +900,3 @@ DLL_API void annMaxPtsVisit( // max. pts to visit in search
     int maxPts);             // the limit
 
 DLL_API void annClose(); // called to end use of ANN
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/ANN/ANNperf.h b/Framework/Kernel/inc/MantidKernel/ANN/ANNperf.h
index 7f697d5161c..042732e1f37 100644
--- a/Framework/Kernel/inc/MantidKernel/ANN/ANNperf.h
+++ b/Framework/Kernel/inc/MantidKernel/ANN/ANNperf.h
@@ -27,8 +27,7 @@
 //          Added ANN_ prefix to avoid name conflicts.
 //----------------------------------------------------------------------
 
-#ifndef ANNperf_H
-#define ANNperf_H
+#pragma once
 
 //----------------------------------------------------------------------
 //	basic includes
@@ -232,5 +231,3 @@ DLL_API void annResetCounts(); // reset counts for one queries
 DLL_API void annUpdateStats(); // update stats with current counts
 
 DLL_API void annPrintStats(ANNbool validate); // print statistics for a run
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/ANN/ANNx.h b/Framework/Kernel/inc/MantidKernel/ANN/ANNx.h
index 898cc2bfd1f..22d859821f5 100644
--- a/Framework/Kernel/inc/MantidKernel/ANN/ANNx.h
+++ b/Framework/Kernel/inc/MantidKernel/ANN/ANNx.h
@@ -33,8 +33,7 @@
 //		Fixed minor compilation bugs for new versions of gcc
 //----------------------------------------------------------------------
 
-#ifndef ANNx_H
-#define ANNx_H
+#pragma once
 
 #include "MantidKernel/ANN/ANN.h" // ANN includes
 #include <iomanip>                // I/O manipulators
@@ -204,5 +203,3 @@ public:
 
 // array of halfspaces
 using ANNorthHSArray = ANNorthHalfSpace *;
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/ArrayBoundedValidator.h b/Framework/Kernel/inc/MantidKernel/ArrayBoundedValidator.h
index 28a71867919..cfec1b32149 100644
--- a/Framework/Kernel/inc/MantidKernel/ArrayBoundedValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/ArrayBoundedValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ARRAYBOUNDEDVALIDATOR_H_
-#define MANTID_KERNEL_ARRAYBOUNDEDVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/BoundedValidator.h"
 
@@ -68,5 +67,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ARRAYBOUNDEDVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ArrayLengthValidator.h b/Framework/Kernel/inc/MantidKernel/ArrayLengthValidator.h
index 4d3cc2e86be..ebba6492868 100644
--- a/Framework/Kernel/inc/MantidKernel/ArrayLengthValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/ArrayLengthValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ARRAYLENGTHVALIDATOR_H_
-#define MANTID_KERNEL_ARRAYLENGTHVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -73,5 +72,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ARRAYLENGTHVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ArrayOrderedPairsValidator.h b/Framework/Kernel/inc/MantidKernel/ArrayOrderedPairsValidator.h
index 4ff468ba687..34609e99512 100644
--- a/Framework/Kernel/inc/MantidKernel/ArrayOrderedPairsValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/ArrayOrderedPairsValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ARRAYORDEREDPAIRSVALIDATOR_H_
-#define MANTID_KERNEL_ARRAYORDEREDPAIRSVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -34,5 +33,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ARRAYORDEREDPAIRSVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ArrayProperty.h b/Framework/Kernel/inc/MantidKernel/ArrayProperty.h
index 17da6e6dd46..fe7832a5a0b 100644
--- a/Framework/Kernel/inc/MantidKernel/ArrayProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/ArrayProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ARRAYPROPERTY_H_
-#define MANTID_KERNEL_ARRAYPROPERTY_H_
+#pragma once
 
 #include "DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -66,5 +65,3 @@ MANTID_KERNEL_DLL void ArrayProperty<int>::visualStudioC4661Workaround();
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_ARRAYPROPERTY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/Atom.h b/Framework/Kernel/inc/MantidKernel/Atom.h
index 84abe742eb5..1312f7446ee 100644
--- a/Framework/Kernel/inc/MantidKernel/Atom.h
+++ b/Framework/Kernel/inc/MantidKernel/Atom.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ATOM_H_
-#define ATOM_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/NeutronAtom.h"
@@ -71,5 +70,3 @@ MANTID_KERNEL_DLL const Atom &getAtom(const std::string &symbol,
 
 } // namespace PhysicalConstants
 } // namespace Mantid
-
-#endif /* ATOM_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/BinFinder.h b/Framework/Kernel/inc/MantidKernel/BinFinder.h
index 35e856e47c5..2e6e880538f 100644
--- a/Framework/Kernel/inc/MantidKernel/BinFinder.h
+++ b/Framework/Kernel/inc/MantidKernel/BinFinder.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BINFINDER_H
-#define BINFINDER_H
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -53,5 +52,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*BINFINDER_H*/
diff --git a/Framework/Kernel/inc/MantidKernel/BinaryFile.h b/Framework/Kernel/inc/MantidKernel/BinaryFile.h
index a35593c406f..9137fa2f68e 100644
--- a/Framework/Kernel/inc/MantidKernel/BinaryFile.h
+++ b/Framework/Kernel/inc/MantidKernel/BinaryFile.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BINARYFILE_H_
-#define BINARYFILE_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -273,5 +272,3 @@ private:
 } // Namespace Kernel
 
 } // Namespace Mantid
-
-#endif /* BINARYFILE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/BinaryStreamReader.h b/Framework/Kernel/inc/MantidKernel/BinaryStreamReader.h
index c9f91530559..847569d990f 100644
--- a/Framework/Kernel/inc/MantidKernel/BinaryStreamReader.h
+++ b/Framework/Kernel/inc/MantidKernel/BinaryStreamReader.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_BINARYSTREAMREADER_H_
-#define MANTID_KERNEL_BINARYSTREAMREADER_H_
+#pragma once
 //------------------------------------------------------------------------------
 // Includes
 //------------------------------------------------------------------------------
@@ -86,5 +85,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_BINARYSTREAMREADER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/BinaryStreamWriter.h b/Framework/Kernel/inc/MantidKernel/BinaryStreamWriter.h
index bfb1bec2552..19cf8440e2a 100644
--- a/Framework/Kernel/inc/MantidKernel/BinaryStreamWriter.h
+++ b/Framework/Kernel/inc/MantidKernel/BinaryStreamWriter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_BINARYSTREAMWRITER_H_
-#define MANTID_KERNEL_BINARYSTREAMWRITER_H_
+#pragma once
 //------------------------------------------------------------------------------
 // Includes
 //------------------------------------------------------------------------------
@@ -88,5 +87,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_BINARYSTREAMWRITER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/BoundedValidator.h b/Framework/Kernel/inc/MantidKernel/BoundedValidator.h
index 515f6a3382c..1ce7f6af943 100644
--- a/Framework/Kernel/inc/MantidKernel/BoundedValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/BoundedValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_BOUNDEDVALIDATOR_H_
-#define MANTID_KERNEL_BOUNDEDVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/TypedValidator.h"
 #include <boost/make_shared.hpp>
@@ -158,5 +157,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_BOUNDEDVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/CPUTimer.h b/Framework/Kernel/inc/MantidKernel/CPUTimer.h
index 667af61a82f..03560c19d1f 100644
--- a/Framework/Kernel/inc/MantidKernel/CPUTimer.h
+++ b/Framework/Kernel/inc/MantidKernel/CPUTimer.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CPUTIMER_H_
-#define MANTID_KERNEL_CPUTIMER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Timer.h"
@@ -43,5 +42,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &, CPUTimer &);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CPUTIMER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Cache.h b/Framework/Kernel/inc/MantidKernel/Cache.h
index 8c9b38d56ee..8678c193d50 100644
--- a/Framework/Kernel/inc/MantidKernel/Cache.h
+++ b/Framework/Kernel/inc/MantidKernel/Cache.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CACHE_H_
-#define MANTID_KERNEL_CACHE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -160,5 +159,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_CACHE_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/CaseInsensitiveMap.h b/Framework/Kernel/inc/MantidKernel/CaseInsensitiveMap.h
index 7cf35f59c9b..d0f02fd9c5b 100644
--- a/Framework/Kernel/inc/MantidKernel/CaseInsensitiveMap.h
+++ b/Framework/Kernel/inc/MantidKernel/CaseInsensitiveMap.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CASE_INSENSITIVE_MAP_H
-#define MANTID_KERNEL_CASE_INSENSITIVE_MAP_H
+#pragma once
 
 #include <cstring>
 #include <map>
@@ -33,5 +32,3 @@ using CaseInsensitiveMap =
     std::map<std::string, T, CaseInsensitiveStringComparator>;
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_CASE_INSENSITIVE_MAP_H
diff --git a/Framework/Kernel/inc/MantidKernel/CatalogInfo.h b/Framework/Kernel/inc/MantidKernel/CatalogInfo.h
index e2565e40044..812b3f7baa3 100644
--- a/Framework/Kernel/inc/MantidKernel/CatalogInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/CatalogInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CATALOGINFO_H_
-#define MANTID_KERNEL_CATALOGINFO_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -72,5 +71,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CATALOGINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Chainable.h b/Framework/Kernel/inc/MantidKernel/Chainable.h
index 1f3347440f8..584ab9c6ee2 100644
--- a/Framework/Kernel/inc/MantidKernel/Chainable.h
+++ b/Framework/Kernel/inc/MantidKernel/Chainable.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHAINABLE_H_
-#define MANTID_KERNEL_CHAINABLE_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <memory>
@@ -54,5 +53,3 @@ Chainable<ChainableType>::~Chainable() = default;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CHAINABLE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ChainableFactory.h b/Framework/Kernel/inc/MantidKernel/ChainableFactory.h
index 643fe3ca3c1..559d4593ac9 100644
--- a/Framework/Kernel/inc/MantidKernel/ChainableFactory.h
+++ b/Framework/Kernel/inc/MantidKernel/ChainableFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHAINABLEFACTORY_H_
-#define MANTID_KERNEL_CHAINABLEFACTORY_H_
+#pragma once
 
 #include "MantidKernel/Chainable.h"
 #include "MantidKernel/System.h"
@@ -47,5 +46,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CHAINABLEFACTORY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ChecksumHelper.h b/Framework/Kernel/inc/MantidKernel/ChecksumHelper.h
index 4aac69bf114..0bbf0eb40da 100644
--- a/Framework/Kernel/inc/MantidKernel/ChecksumHelper.h
+++ b/Framework/Kernel/inc/MantidKernel/ChecksumHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHECKSUMHELPER_H_
-#define MANTID_KERNEL_CHECKSUMHELPER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -30,5 +29,3 @@ MANTID_KERNEL_DLL std::string gitSha1FromFile(const std::string &filepath);
 } // namespace ChecksumHelper
 
 } // namespace Mantid::Kernel
-
-#endif /* MANTID_KERNEL_CHECKSUMHELPER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/CompositeValidator.h b/Framework/Kernel/inc/MantidKernel/CompositeValidator.h
index 34784d8cb30..8ede2c19a4f 100644
--- a/Framework/Kernel/inc/MantidKernel/CompositeValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/CompositeValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_COMPOSITEVALIDATOR_H_
-#define MANTID_KERNEL_COMPOSITEVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/IValidator.h"
 #include "MantidKernel/System.h"
@@ -86,5 +85,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_COMPOSITEVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ComputeResourceInfo.h b/Framework/Kernel/inc/MantidKernel/ComputeResourceInfo.h
index f26b3db6afa..d11f73f1a1d 100644
--- a/Framework/Kernel/inc/MantidKernel/ComputeResourceInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/ComputeResourceInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_COMPUTERESOURCEINFO_H_
-#define MANTID_KERNEL_COMPUTERESOURCEINFO_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -64,5 +63,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &buffer,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_COMPUTERESOURCEINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ConfigObserver.h b/Framework/Kernel/inc/MantidKernel/ConfigObserver.h
index c3730b01ca6..f11597f00f6 100644
--- a/Framework/Kernel/inc/MantidKernel/ConfigObserver.h
+++ b/Framework/Kernel/inc/MantidKernel/ConfigObserver.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CONFIGOBSERVER_H_
-#define MANTID_KERNEL_CONFIGOBSERVER_H_
+#pragma once
 #include "ConfigService.h"
 #include "MantidKernel/DllConfig.h"
 #include "Poco/NObserver.h"
@@ -36,5 +35,4 @@ private:
       m_valueChangeListener;
 };
 } // namespace Kernel
-} // namespace Mantid
-#endif /*MANTID_KERNEL_CONFIGOBSERVER_H_*/
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/ConfigPropertyObserver.h b/Framework/Kernel/inc/MantidKernel/ConfigPropertyObserver.h
index 8cdd3d2db1d..1fda11589d5 100644
--- a/Framework/Kernel/inc/MantidKernel/ConfigPropertyObserver.h
+++ b/Framework/Kernel/inc/MantidKernel/ConfigPropertyObserver.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CONFIGPROPERTYOBSERVER_H_
-#define MANTID_KERNEL_CONFIGPROPERTYOBSERVER_H_
+#pragma once
 #include "ConfigObserver.h"
 #include "ConfigService.h"
 #include "MantidKernel/DllConfig.h"
@@ -31,5 +30,4 @@ private:
   std::string m_propertyName;
 };
 } // namespace Kernel
-} // namespace Mantid
-#endif /*MANTID_KERNEL_CONFIGPROPERTYOBSERVER_H_*/
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/ConfigService.h b/Framework/Kernel/inc/MantidKernel/ConfigService.h
index c9a5fb81276..51dd8b0f159 100644
--- a/Framework/Kernel/inc/MantidKernel/ConfigService.h
+++ b/Framework/Kernel/inc/MantidKernel/ConfigService.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CONFIGSERVICE_H_
-#define MANTID_KERNEL_CONFIGSERVICE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -337,5 +336,3 @@ using ConfigValChangeNotification_ptr =
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_CONFIGSERVICE_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/DataItem.h b/Framework/Kernel/inc/MantidKernel/DataItem.h
index 2e3c500c791..81d3801b468 100644
--- a/Framework/Kernel/inc/MantidKernel/DataItem.h
+++ b/Framework/Kernel/inc/MantidKernel/DataItem.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATAITEM_H_
-#define MANTID_KERNEL_DATAITEM_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -83,5 +82,3 @@ using DataItem_const_sptr = boost::shared_ptr<const DataItem>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_DATAITEM_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/DataService.h b/Framework/Kernel/inc/MantidKernel/DataService.h
index a2fd738b5c8..9fd929a190d 100644
--- a/Framework/Kernel/inc/MantidKernel/DataService.h
+++ b/Framework/Kernel/inc/MantidKernel/DataService.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATASERVICE_H_
-#define MANTID_KERNEL_DATASERVICE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -547,5 +546,3 @@ private:
 
 } // Namespace Kernel
 } // Namespace Mantid
-
-#endif /*MANTID_KERNEL_DATASERVICE_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/DateAndTime.h b/Framework/Kernel/inc/MantidKernel/DateAndTime.h
index 99298e7a502..f6945e80740 100644
--- a/Framework/Kernel/inc/MantidKernel/DateAndTime.h
+++ b/Framework/Kernel/inc/MantidKernel/DateAndTime.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef DATE_AND_TIME_H
-#define DATE_AND_TIME_H
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidTypes/Core/DateAndTime.h"
@@ -66,5 +65,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // DATE_AND_TIME_H
diff --git a/Framework/Kernel/inc/MantidKernel/DateAndTimeHelpers.h b/Framework/Kernel/inc/MantidKernel/DateAndTimeHelpers.h
index 4eb8aa8d0bf..846fcc2fca5 100644
--- a/Framework/Kernel/inc/MantidKernel/DateAndTimeHelpers.h
+++ b/Framework/Kernel/inc/MantidKernel/DateAndTimeHelpers.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATEANDTIMEHELPERS_H_
-#define MANTID_KERNEL_DATEANDTIMEHELPERS_H_
+#pragma once
 
 #include "MantidKernel/DateAndTime.h"
 #include "MantidKernel/DllConfig.h"
@@ -31,5 +30,3 @@ averageSorted(const std::vector<Types::Core::DateAndTime> &times,
 } // namespace DateAndTimeHelpers
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_DATEANDTIMEHELPERS_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/DateTimeValidator.h b/Framework/Kernel/inc/MantidKernel/DateTimeValidator.h
index bdd666f5028..f9fbdc36163 100644
--- a/Framework/Kernel/inc/MantidKernel/DateTimeValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/DateTimeValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATETIMEVALIDATOR_H_
-#define MANTID_KERNEL_DATETIMEVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -36,5 +35,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /** DATETIMEVALIDATOR */
diff --git a/Framework/Kernel/inc/MantidKernel/DateValidator.h b/Framework/Kernel/inc/MantidKernel/DateValidator.h
index bf9ff831a56..ad9f8f8ad01 100644
--- a/Framework/Kernel/inc/MantidKernel/DateValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/DateValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATEVALIDATOR_H_
-#define MANTID_KERNEL_DATEVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -35,5 +34,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/DeltaEMode.h b/Framework/Kernel/inc/MantidKernel/DeltaEMode.h
index 4cc08c608e6..614454b6887 100644
--- a/Framework/Kernel/inc/MantidKernel/DeltaEMode.h
+++ b/Framework/Kernel/inc/MantidKernel/DeltaEMode.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DELTAEMODE_H_
-#define MANTID_KERNEL_DELTAEMODE_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -45,5 +44,3 @@ struct MANTID_KERNEL_DLL DeltaEMode {
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_DELTAEMODE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Diffraction.h b/Framework/Kernel/inc/MantidKernel/Diffraction.h
index af184b1d52e..ce2826cdf77 100644
--- a/Framework/Kernel/inc/MantidKernel/Diffraction.h
+++ b/Framework/Kernel/inc/MantidKernel/Diffraction.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DIFFRACTION_H_
-#define MANTID_KERNEL_DIFFRACTION_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <functional>
@@ -35,5 +34,3 @@ getDToTofConversionFunc(const double difc, const double difa,
 } // namespace Diffraction
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_DIFFRACTION_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/DirectoryValidator.h b/Framework/Kernel/inc/MantidKernel/DirectoryValidator.h
index 51d799fab1c..d4abfb7c114 100644
--- a/Framework/Kernel/inc/MantidKernel/DirectoryValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/DirectoryValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DirectoryValidator_H_
-#define MANTID_KERNEL_DirectoryValidator_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -37,5 +36,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_DirectoryValidator_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/DiskBuffer.h b/Framework/Kernel/inc/MantidKernel/DiskBuffer.h
index ddd0eb747bc..9ceb90d00ff 100644
--- a/Framework/Kernel/inc/MantidKernel/DiskBuffer.h
+++ b/Framework/Kernel/inc/MantidKernel/DiskBuffer.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DISKBUFFER_H_
-#define MANTID_KERNEL_DISKBUFFER_H_
+#pragma once
 
 #include "MantidKernel/FreeBlock.h"
 #include "MantidKernel/System.h"
@@ -157,5 +156,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_DISKBUFFER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/DllConfig.h b/Framework/Kernel/inc/MantidKernel/DllConfig.h
index da138654bc3..50f181a490b 100644
--- a/Framework/Kernel/inc/MantidKernel/DllConfig.h
+++ b/Framework/Kernel/inc/MantidKernel/DllConfig.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DLLCONFIG_H_
-#define MANTID_KERNEL_DLLCONFIG_H_
+#pragma once
 
 /*
     This file contains the DLLExport/DLLImport linkage configuration for the
@@ -22,5 +21,3 @@
 #define MANTID_KERNEL_DLL DLLImport
 #define EXTERN_MANTID_KERNEL EXTERN_IMPORT
 #endif /* IN_MANTID_KERNEL*/
-
-#endif // MANTID_KERNEL_DLLCONFIG_H_
diff --git a/Framework/Kernel/inc/MantidKernel/DllOpen.h b/Framework/Kernel/inc/MantidKernel/DllOpen.h
index c2f9796a4e2..48c8ef4b38a 100644
--- a/Framework/Kernel/inc/MantidKernel/DllOpen.h
+++ b/Framework/Kernel/inc/MantidKernel/DllOpen.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DLLOPEN_H_
-#define MANTID_KERNEL_DLLOPEN_H_
+#pragma once
 
 #include <string>
 
@@ -45,5 +44,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_DLLOPEN_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/DocumentationHeader.h b/Framework/Kernel/inc/MantidKernel/DocumentationHeader.h
index 371fb092145..23e9cdfb617 100644
--- a/Framework/Kernel/inc/MantidKernel/DocumentationHeader.h
+++ b/Framework/Kernel/inc/MantidKernel/DocumentationHeader.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DOCUMENTATIONHEADER_H_
-#define MANTID_KERNEL_DOCUMENTATIONHEADER_H_
+#pragma once
 
 // The following stuff is for the doxygen title page
 /**  \mainpage Mantid - Manipulation and Analysis Toolkit for Instrument Data -
@@ -50,5 +49,3 @@ Geometry.  </li>
   Refer to the conding standards page on the project wiki <a
 href="http://www.mantidproject.org/Coding_Standards">here</a>.
 */
-
-#endif /*MANTID_KERNEL_DOCUMENTATIONHEADER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/DynamicFactory.h b/Framework/Kernel/inc/MantidKernel/DynamicFactory.h
index 1910779ea58..4b4b587f586 100644
--- a/Framework/Kernel/inc/MantidKernel/DynamicFactory.h
+++ b/Framework/Kernel/inc/MantidKernel/DynamicFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DYNAMICFACTORY_H_
-#define MANTID_KERNEL_DYNAMICFACTORY_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -222,5 +221,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_DYNAMICFACTORY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/EigenConversionHelpers.h b/Framework/Kernel/inc/MantidKernel/EigenConversionHelpers.h
index 98e79688013..27d8d766950 100644
--- a/Framework/Kernel/inc/MantidKernel/EigenConversionHelpers.h
+++ b/Framework/Kernel/inc/MantidKernel/EigenConversionHelpers.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EIGENCONVERSIONHELPERS_H_
-#define MANTID_KERNEL_EIGENCONVERSIONHELPERS_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Quat.h"
@@ -46,5 +45,3 @@ inline Eigen::Quaterniond toQuaterniond(const Kernel::Quat &quat) {
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_EIGENCONVERSIONHELPERS_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/EmptyValues.h b/Framework/Kernel/inc/MantidKernel/EmptyValues.h
index 1fa64c292bd..6af182cf929 100644
--- a/Framework/Kernel/inc/MantidKernel/EmptyValues.h
+++ b/Framework/Kernel/inc/MantidKernel/EmptyValues.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EMPTYVALUES_H_
-#define MANTID_KERNEL_EMPTYVALUES_H_
+#pragma once
 
 /**
     This file contains functions to define empty values, i.e EMPTY_INT();
@@ -50,5 +49,3 @@ constexpr double EMPTY_DBL() noexcept {
 }
 
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_EMPTYVALUES_H_
diff --git a/Framework/Kernel/inc/MantidKernel/EnabledWhenProperty.h b/Framework/Kernel/inc/MantidKernel/EnabledWhenProperty.h
index a4660b89b16..afc040eb489 100644
--- a/Framework/Kernel/inc/MantidKernel/EnabledWhenProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/EnabledWhenProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ENABLEDWHENPROPERTY_H_
-#define MANTID_KERNEL_ENABLEDWHENPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/IPropertySettings.h"
 #include "MantidKernel/System.h"
@@ -150,5 +149,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ENABLEDWHENPROPERTY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/EnvironmentHistory.h b/Framework/Kernel/inc/MantidKernel/EnvironmentHistory.h
index c5f90736930..2777f48ec4e 100644
--- a/Framework/Kernel/inc/MantidKernel/EnvironmentHistory.h
+++ b/Framework/Kernel/inc/MantidKernel/EnvironmentHistory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ENVIRONMENTHISTORY_H_
-#define MANTID_KERNEL_ENVIRONMENTHISTORY_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -43,5 +42,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_ENVIRONMENTHISTORY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/EqualBinsChecker.h b/Framework/Kernel/inc/MantidKernel/EqualBinsChecker.h
index a61b08aad03..0a77ecfcad1 100644
--- a/Framework/Kernel/inc/MantidKernel/EqualBinsChecker.h
+++ b/Framework/Kernel/inc/MantidKernel/EqualBinsChecker.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EQUALBINSCHECKER_H_
-#define MANTID_KERNEL_EQUALBINSCHECKER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/cow_ptr.h"
@@ -48,5 +47,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_EQUALBINSCHECKER_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/ErrorReporter.h b/Framework/Kernel/inc/MantidKernel/ErrorReporter.h
index 57b40d76688..cbd3351e214 100644
--- a/Framework/Kernel/inc/MantidKernel/ErrorReporter.h
+++ b/Framework/Kernel/inc/MantidKernel/ErrorReporter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ERRORSERVICE_H_
-#define MANTID_KERNEL_ERRORSERVICE_H_
+#pragma once
 
 #include <Poco/ActiveMethod.h>
 #include <string>
@@ -55,5 +54,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ERRORSERVICE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Exception.h b/Framework/Kernel/inc/MantidKernel/Exception.h
index fa3fc740021..8d7de3f1058 100644
--- a/Framework/Kernel/inc/MantidKernel/Exception.h
+++ b/Framework/Kernel/inc/MantidKernel/Exception.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EXCEPTION_H_
-#define MANTID_KERNEL_EXCEPTION_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -347,5 +346,3 @@ public:
 } // namespace Exception
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_EXCEPTION_H_
diff --git a/Framework/Kernel/inc/MantidKernel/FacilityInfo.h b/Framework/Kernel/inc/MantidKernel/FacilityInfo.h
index 963337b9ca8..fad7dc81db7 100644
--- a/Framework/Kernel/inc/MantidKernel/FacilityInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/FacilityInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FACILITYINFO_H_
-#define MANTID_KERNEL_FACILITYINFO_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -131,5 +130,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_FACILITYINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Fast_Exponential.h b/Framework/Kernel/inc/MantidKernel/Fast_Exponential.h
index 737ed7253d9..0cdf9751537 100644
--- a/Framework/Kernel/inc/MantidKernel/Fast_Exponential.h
+++ b/Framework/Kernel/inc/MantidKernel/Fast_Exponential.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FAST_EXPONENTIAL_H_
-#define MANTID_KERNEL_FAST_EXPONENTIAL_H_
+#pragma once
 
 namespace Mantid {
 namespace Kernel {
@@ -49,5 +48,3 @@ inline double fast_exp(double y) {
 
 } // Namespace Kernel
 } // Namespace Mantid
-
-#endif /* FAST_EXPOENTIAL_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/FileDescriptor.h b/Framework/Kernel/inc/MantidKernel/FileDescriptor.h
index 48949e235cc..a6ed1bd79ed 100644
--- a/Framework/Kernel/inc/MantidKernel/FileDescriptor.h
+++ b/Framework/Kernel/inc/MantidKernel/FileDescriptor.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FILEDESCRIPTOR_H_
-#define MANTID_KERNEL_FILEDESCRIPTOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -91,5 +90,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_FILEDESCRIPTOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/FileValidator.h b/Framework/Kernel/inc/MantidKernel/FileValidator.h
index 36cd5fba149..40c23981b9f 100644
--- a/Framework/Kernel/inc/MantidKernel/FileValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/FileValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FILEVALIDATOR_H_
-#define MANTID_KERNEL_FILEVALIDATOR_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -44,5 +43,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_FILEVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/FilteredTimeSeriesProperty.h b/Framework/Kernel/inc/MantidKernel/FilteredTimeSeriesProperty.h
index 32d291c7c1d..f8162136db1 100644
--- a/Framework/Kernel/inc/MantidKernel/FilteredTimeSeriesProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/FilteredTimeSeriesProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FILTEREDTIMESERIESPROPERTY_H_
-#define MANTID_KERNEL_FILTEREDTIMESERIESPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/System.h"
@@ -48,5 +47,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_FILTEREDTIMESERIESPROPERTY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/FloatingPointComparison.h b/Framework/Kernel/inc/MantidKernel/FloatingPointComparison.h
index af31acd334e..ce6ab78dfed 100644
--- a/Framework/Kernel/inc/MantidKernel/FloatingPointComparison.h
+++ b/Framework/Kernel/inc/MantidKernel/FloatingPointComparison.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FLOATINGPOINTCOMPARISON_H_
-#define MANTID_KERNEL_FLOATINGPOINTCOMPARISON_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -22,5 +21,3 @@ template <typename T> MANTID_KERNEL_DLL bool ltEquals(const T x, const T y);
 template <typename T> MANTID_KERNEL_DLL bool gtEquals(const T x, const T y);
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_FLOATINGPOINTCOMPARISON_H_
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/FreeBlock.h b/Framework/Kernel/inc/MantidKernel/FreeBlock.h
index 23b929b8211..e937dffaa7b 100644
--- a/Framework/Kernel/inc/MantidKernel/FreeBlock.h
+++ b/Framework/Kernel/inc/MantidKernel/FreeBlock.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_API_FREEBLOCK_H_
-#define MANTID_API_FREEBLOCK_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 
@@ -64,5 +63,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_API_FREEBLOCK_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/FunctionTask.h b/Framework/Kernel/inc/MantidKernel/FunctionTask.h
index 9b561ac92ab..8975c93051f 100644
--- a/Framework/Kernel/inc/MantidKernel/FunctionTask.h
+++ b/Framework/Kernel/inc/MantidKernel/FunctionTask.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FUNCTIONTASK_H_
-#define MANTID_KERNEL_FUNCTIONTASK_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Task.h"
@@ -79,5 +78,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_FUNCTIONTASK_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Glob.h b/Framework/Kernel/inc/MantidKernel/Glob.h
index 06dbde6d17f..870a908ce46 100644
--- a/Framework/Kernel/inc/MantidKernel/Glob.h
+++ b/Framework/Kernel/inc/MantidKernel/Glob.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_GLOB_H_
-#define MANTID_KERNEL_GLOB_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -35,5 +34,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_GLOB_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/ICatalogInfo.h b/Framework/Kernel/inc/MantidKernel/ICatalogInfo.h
index f3f5ea2a25e..23aa1225899 100644
--- a/Framework/Kernel/inc/MantidKernel/ICatalogInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/ICatalogInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ICATALOGINFO_H_
-#define MANTID_KERNEL_ICATALOGINFO_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -52,5 +51,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ICATALOGINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/INode.h b/Framework/Kernel/inc/MantidKernel/INode.h
index d1ec7a7cf0d..ed44ebcf5a8 100644
--- a/Framework/Kernel/inc/MantidKernel/INode.h
+++ b/Framework/Kernel/inc/MantidKernel/INode.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef INODE_H_
-#define INODE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -22,5 +21,3 @@ public:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/IPropertyManager.h b/Framework/Kernel/inc/MantidKernel/IPropertyManager.h
index ef28254cb5b..b7e1089c00f 100644
--- a/Framework/Kernel/inc/MantidKernel/IPropertyManager.h
+++ b/Framework/Kernel/inc/MantidKernel/IPropertyManager.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_IPROPERTYMANAGER_H_
-#define MANTID_KERNEL_IPROPERTYMANAGER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IValidator.h"
@@ -572,5 +571,3 @@ private:
   }                                                                            \
   }                                                                            \
   }
-
-#endif /*MANTID_KERNEL_IPROPERTYMANAGER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/IPropertySettings.h b/Framework/Kernel/inc/MantidKernel/IPropertySettings.h
index f88af885c8f..250574e3554 100644
--- a/Framework/Kernel/inc/MantidKernel/IPropertySettings.h
+++ b/Framework/Kernel/inc/MantidKernel/IPropertySettings.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_IPROPERTYSETTINGS_H_
-#define MANTID_KERNEL_IPROPERTYSETTINGS_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 
@@ -79,5 +78,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_IPROPERTYSETTINGS_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ISaveable.h b/Framework/Kernel/inc/MantidKernel/ISaveable.h
index 49f77db4866..4b45a284851 100644
--- a/Framework/Kernel/inc/MantidKernel/ISaveable.h
+++ b/Framework/Kernel/inc/MantidKernel/ISaveable.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ISAVEABLE_H_
-#define MANTID_KERNEL_ISAVEABLE_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <list>
@@ -178,5 +177,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_ISAVEABLE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ITimeSeriesProperty.h b/Framework/Kernel/inc/MantidKernel/ITimeSeriesProperty.h
index b223c2536d4..d7bf44bac00 100644
--- a/Framework/Kernel/inc/MantidKernel/ITimeSeriesProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/ITimeSeriesProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ITIMESERIESPROPERTY_H_
-#define MANTID_KERNEL_ITIMESERIESPROPERTY_H_
+#pragma once
 
 #include <vector>
 
@@ -61,5 +60,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_ITIMESERIESPROPERTY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/IValidator.h b/Framework/Kernel/inc/MantidKernel/IValidator.h
index f52c80ec284..9e2108a043a 100644
--- a/Framework/Kernel/inc/MantidKernel/IValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/IValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_IVALIDATOR_H_
-#define MANTID_KERNEL_IVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/DataItem.h"
 #include "MantidKernel/DllConfig.h"
@@ -163,5 +162,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_IVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/IndexSet.h b/Framework/Kernel/inc/MantidKernel/IndexSet.h
index 85c8e33fd38..5dac14c2f29 100644
--- a/Framework/Kernel/inc/MantidKernel/IndexSet.h
+++ b/Framework/Kernel/inc/MantidKernel/IndexSet.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INDEXSET_H_
-#define MANTID_KERNEL_INDEXSET_H_
+#pragma once
 
 #include <vector>
 
@@ -51,5 +50,3 @@ private:
 
 } // Namespace Kernel
 } // Namespace Mantid
-
-#endif /* MANTID_KERNEL_INDEXSET_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Instantiator.h b/Framework/Kernel/inc/MantidKernel/Instantiator.h
index b572334f71a..5ecce08a045 100644
--- a/Framework/Kernel/inc/MantidKernel/Instantiator.h
+++ b/Framework/Kernel/inc/MantidKernel/Instantiator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INSTANTIATOR_H_
-#define MANTID_KERNEL_INSTANTIATOR_H_
+#pragma once
 
 #ifndef Q_MOC_RUN
 #include <boost/shared_ptr.hpp>
@@ -77,5 +76,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_INSTANTIATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/InstrumentInfo.h b/Framework/Kernel/inc/MantidKernel/InstrumentInfo.h
index 4077c820405..3c982650d51 100644
--- a/Framework/Kernel/inc/MantidKernel/InstrumentInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/InstrumentInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INSTRUMENTINFO_H_
-#define MANTID_KERNEL_INSTRUMENTINFO_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -107,5 +106,3 @@ operator<<(std::ostream &buffer, const InstrumentInfo &instrumentDescriptor);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_INSTRUMENTINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/InternetHelper.h b/Framework/Kernel/inc/MantidKernel/InternetHelper.h
index 9b15a860223..7716b026783 100644
--- a/Framework/Kernel/inc/MantidKernel/InternetHelper.h
+++ b/Framework/Kernel/inc/MantidKernel/InternetHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_InternetHelper_H_
-#define MANTID_KERNEL_InternetHelper_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/ProxyInfo.h"
@@ -164,5 +163,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_InternetHelper_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Interpolation.h b/Framework/Kernel/inc/MantidKernel/Interpolation.h
index 295c27cea01..dc2820850be 100644
--- a/Framework/Kernel/inc/MantidKernel/Interpolation.h
+++ b/Framework/Kernel/inc/MantidKernel/Interpolation.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INTERPOLATION_H_
-#define MANTID_KERNEL_INTERPOLATION_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -91,5 +90,3 @@ MANTID_KERNEL_DLL std::istream &operator>>(std::istream &, Interpolation &);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_INTERPOLATION_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/InvisibleProperty.h b/Framework/Kernel/inc/MantidKernel/InvisibleProperty.h
index eafc0dd6bef..4060ef0faee 100644
--- a/Framework/Kernel/inc/MantidKernel/InvisibleProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/InvisibleProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INVISIBLEPROPERTY_H_
-#define MANTID_KERNEL_INVISIBLEPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/IPropertySettings.h"
@@ -23,5 +22,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_INVISIBLEPROPERTY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/LibraryManager.h b/Framework/Kernel/inc/MantidKernel/LibraryManager.h
index 8ca3f201c1c..450194d3497 100644
--- a/Framework/Kernel/inc/MantidKernel/LibraryManager.h
+++ b/Framework/Kernel/inc/MantidKernel/LibraryManager.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LIBRARY_MANAGER_H_
-#define MANTID_KERNEL_LIBRARY_MANAGER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -72,5 +71,3 @@ using LibraryManager = Mantid::Kernel::SingletonHolder<LibraryManagerImpl>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_LIBRARY_MANAGER_H_
diff --git a/Framework/Kernel/inc/MantidKernel/LibraryWrapper.h b/Framework/Kernel/inc/MantidKernel/LibraryWrapper.h
index d1512738ca9..286f00dbb10 100644
--- a/Framework/Kernel/inc/MantidKernel/LibraryWrapper.h
+++ b/Framework/Kernel/inc/MantidKernel/LibraryWrapper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LIBRARY_WRAPPER_H_
-#define MANTID_KERNEL_LIBRARY_WRAPPER_H_
+#pragma once
 
 #include <string>
 
@@ -45,5 +44,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_LIBRARY_WRAPPER_H_
diff --git a/Framework/Kernel/inc/MantidKernel/ListValidator.h b/Framework/Kernel/inc/MantidKernel/ListValidator.h
index f763b374bbd..4087dd04b03 100644
--- a/Framework/Kernel/inc/MantidKernel/ListValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/ListValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LISTVALIDATOR_H_
-#define MANTID_KERNEL_LISTVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/TypedValidator.h"
@@ -185,5 +184,3 @@ using StringListValidator = ListValidator<std::string>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_LISTVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/LiveListenerInfo.h b/Framework/Kernel/inc/MantidKernel/LiveListenerInfo.h
index 8b61ba774c7..ea825cd54ee 100644
--- a/Framework/Kernel/inc/MantidKernel/LiveListenerInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/LiveListenerInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LIVELISTENERINFO_H_
-#define MANTID_KERNEL_LIVELISTENERINFO_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -66,5 +65,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &buffer,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_LIVELISTENERINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/LogFilter.h b/Framework/Kernel/inc/MantidKernel/LogFilter.h
index 6e1e2aeb2ab..7fa44e69bdf 100644
--- a/Framework/Kernel/inc/MantidKernel/LogFilter.h
+++ b/Framework/Kernel/inc/MantidKernel/LogFilter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LOGFILTER_H_
-#define MANTID_KERNEL_LOGFILTER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -69,5 +68,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // LOG_FILTER_H
diff --git a/Framework/Kernel/inc/MantidKernel/LogParser.h b/Framework/Kernel/inc/MantidKernel/LogParser.h
index 9deaab2abbf..40e956864a0 100644
--- a/Framework/Kernel/inc/MantidKernel/LogParser.h
+++ b/Framework/Kernel/inc/MantidKernel/LogParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LOGPARSER_H_
-#define MANTID_KERNEL_LOGPARSER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -121,5 +120,3 @@ MANTID_KERNEL_DLL double timeMean(const Kernel::Property *p);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_LOGPARSER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/Logger.h b/Framework/Kernel/inc/MantidKernel/Logger.h
index 9c8bd4c5ef8..5f3e4c96a8b 100644
--- a/Framework/Kernel/inc/MantidKernel/Logger.h
+++ b/Framework/Kernel/inc/MantidKernel/Logger.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LOGGINGSERVICE_H_
-#define MANTID_KERNEL_LOGGINGSERVICE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -152,5 +151,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_LOGGINGSERVICE_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/MDAxisValidator.h b/Framework/Kernel/inc/MantidKernel/MDAxisValidator.h
index a54c313a896..041dc3720ca 100644
--- a/Framework/Kernel/inc/MantidKernel/MDAxisValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/MDAxisValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDAXISVALIDATOR_H_
-#define MANTID_KERNEL_MDAXISVALIDATOR_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -42,5 +41,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MDAXISVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MDUnit.h b/Framework/Kernel/inc/MantidKernel/MDUnit.h
index d2cfdd61c0c..47ad7a893cb 100644
--- a/Framework/Kernel/inc/MantidKernel/MDUnit.h
+++ b/Framework/Kernel/inc/MantidKernel/MDUnit.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDUNIT_H_
-#define MANTID_KERNEL_MDUNIT_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/UnitLabel.h"
@@ -73,5 +72,3 @@ using MDUnit_const_uptr = std::unique_ptr<const MDUnit>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MDUNIT_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MDUnitFactory.h b/Framework/Kernel/inc/MantidKernel/MDUnitFactory.h
index a86db334f0d..2c2baad3aae 100644
--- a/Framework/Kernel/inc/MantidKernel/MDUnitFactory.h
+++ b/Framework/Kernel/inc/MantidKernel/MDUnitFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDUNITFACTORY_H_
-#define MANTID_KERNEL_MDUNITFACTORY_H_
+#pragma once
 
 #include "MantidKernel/ChainableFactory.h"
 #include "MantidKernel/DllConfig.h"
@@ -59,5 +58,3 @@ MDUnitFactory_uptr MANTID_KERNEL_DLL makeMDUnitFactoryChain();
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MDUNITFACTORY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MRUList.h b/Framework/Kernel/inc/MantidKernel/MRUList.h
index d13706a894b..4e03b7294ba 100644
--- a/Framework/Kernel/inc/MantidKernel/MRUList.h
+++ b/Framework/Kernel/inc/MantidKernel/MRUList.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MRULIST_H
-#define MANTID_KERNEL_MRULIST_H
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -158,5 +157,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_MRULIST_H
diff --git a/Framework/Kernel/inc/MantidKernel/MagneticIon.h b/Framework/Kernel/inc/MantidKernel/MagneticIon.h
index 04bfc8b879b..0bca56a9294 100644
--- a/Framework/Kernel/inc/MantidKernel/MagneticIon.h
+++ b/Framework/Kernel/inc/MantidKernel/MagneticIon.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MAGNETICION_H_
-#define MAGNETICION_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -74,5 +73,3 @@ MANTID_KERNEL_DLL std::vector<std::string> getMagneticIonList();
 
 } // namespace PhysicalConstants
 } // namespace Mantid
-
-#endif /* MAGNETICION_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MandatoryValidator.h b/Framework/Kernel/inc/MantidKernel/MandatoryValidator.h
index d1b95b5c5bf..37ce83994d5 100644
--- a/Framework/Kernel/inc/MantidKernel/MandatoryValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/MandatoryValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MANDATORYVALIDATOR_H_
-#define MANTID_KERNEL_MANDATORYVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/TypedValidator.h"
 #include <boost/make_shared.hpp>
@@ -66,5 +65,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_MANDATORYVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/MantidVersion.h b/Framework/Kernel/inc/MantidKernel/MantidVersion.h
index cf275d2d716..5fd636774f5 100644
--- a/Framework/Kernel/inc/MantidKernel/MantidVersion.h
+++ b/Framework/Kernel/inc/MantidKernel/MantidVersion.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MANTIDVERSION_H_
-#define MANTID_KERNEL_MANTIDVERSION_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -39,5 +38,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MANTIDVERSION_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MaskedProperty.h b/Framework/Kernel/inc/MantidKernel/MaskedProperty.h
index dcec9ad807a..feab9fb0895 100644
--- a/Framework/Kernel/inc/MantidKernel/MaskedProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/MaskedProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MASKEDPROPERTY_H_
-#define MANTID_KERNEL_MASKEDPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/PropertyWithValue.h"
 #include <string>
@@ -55,5 +54,4 @@ private:
   mutable TYPE m_maskedValue; ///< the masked value
 };
 } // namespace Kernel
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/Material.h b/Framework/Kernel/inc/MantidKernel/Material.h
index 7443c3db769..28d6a7ad735 100644
--- a/Framework/Kernel/inc/MantidKernel/Material.h
+++ b/Framework/Kernel/inc/MantidKernel/Material.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_GEOMETRY_MATERIAL_H_
-#define MANTID_GEOMETRY_MATERIAL_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -211,5 +210,3 @@ using Material_sptr = boost::shared_ptr<Material>;
 using Material_const_sptr = boost::shared_ptr<const Material>;
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_GEOMETRY_MATERIAL_H_
diff --git a/Framework/Kernel/inc/MantidKernel/MaterialBuilder.h b/Framework/Kernel/inc/MantidKernel/MaterialBuilder.h
index 21bb2373c00..2011c8a649f 100644
--- a/Framework/Kernel/inc/MantidKernel/MaterialBuilder.h
+++ b/Framework/Kernel/inc/MantidKernel/MaterialBuilder.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATERIALBUILDER_H_
-#define MANTID_KERNEL_MATERIALBUILDER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Material.h"
@@ -69,5 +68,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MATERIALBUILDER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MaterialXMLParser.h b/Framework/Kernel/inc/MantidKernel/MaterialXMLParser.h
index 8cf75ea15cd..ac95ed46d44 100644
--- a/Framework/Kernel/inc/MantidKernel/MaterialXMLParser.h
+++ b/Framework/Kernel/inc/MantidKernel/MaterialXMLParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATERIALXMLPARSER_H_
-#define MANTID_KERNEL_MATERIALXMLPARSER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Material.h"
@@ -33,5 +32,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_MATERIALXMLPARSER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Math/ChebyshevPolyFit.h b/Framework/Kernel/inc/MantidKernel/Math/ChebyshevPolyFit.h
index 22396658476..66bf4c9a26a 100644
--- a/Framework/Kernel/inc/MantidKernel/Math/ChebyshevPolyFit.h
+++ b/Framework/Kernel/inc/MantidKernel/Math/ChebyshevPolyFit.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVPOLYFIT_H_
-#define MANTID_KERNEL_CHEBYSHEVPOLYFIT_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -43,5 +42,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CHEBYSHEVPOLYFIT_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevPolynomial.h b/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevPolynomial.h
index 058e35aa348..3db443994fb 100644
--- a/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevPolynomial.h
+++ b/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevPolynomial.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVPOLYNOMIAL_H_
-#define MANTID_KERNEL_CHEBYSHEVPOLYNOMIAL_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -25,5 +24,3 @@ struct MANTID_KERNEL_DLL ChebyshevPolynomial {
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CHEBYSHEVPOLYNOMIAL_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevSeries.h b/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevSeries.h
index ec2898a86a2..4629ffd5a7a 100644
--- a/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevSeries.h
+++ b/Framework/Kernel/inc/MantidKernel/Math/Distributions/ChebyshevSeries.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVSERIES_H_
-#define MANTID_KERNEL_CHEBYSHEVSERIES_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -35,5 +34,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_CHEBYSHEVSERIES_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Math/Optimization/SLSQPMinimizer.h b/Framework/Kernel/inc/MantidKernel/Math/Optimization/SLSQPMinimizer.h
index 680790d08c0..40971d3bc13 100644
--- a/Framework/Kernel/inc/MantidKernel/Math/Optimization/SLSQPMinimizer.h
+++ b/Framework/Kernel/inc/MantidKernel/Math/Optimization/SLSQPMinimizer.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SLSQPMINIMIZER_H_
-#define MANTID_KERNEL_SLSQPMINIMIZER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Matrix.h"
@@ -171,5 +170,3 @@ private:
 } // namespace Math
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_SLSQPMINIMIZER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Matrix.h b/Framework/Kernel/inc/MantidKernel/Matrix.h
index 3a7dde83c16..05de6f42292 100644
--- a/Framework/Kernel/inc/MantidKernel/Matrix.h
+++ b/Framework/Kernel/inc/MantidKernel/Matrix.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATRIX_H_
-#define MANTID_KERNEL_MATRIX_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <cfloat>
@@ -232,5 +231,4 @@ std::istream &operator>>(std::istream &, Kernel::Matrix<T> &);
 template <typename T>
 void fillFromStream(std::istream &, Kernel::Matrix<T> &, const char);
 } // namespace Kernel
-} // namespace Mantid
-#endif // MANTID_KERNEL_MATRIX_H_
\ No newline at end of file
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/MatrixProperty.h b/Framework/Kernel/inc/MantidKernel/MatrixProperty.h
index b859fb8659c..2656fe8b34a 100644
--- a/Framework/Kernel/inc/MantidKernel/MatrixProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/MatrixProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATRIXPROPERTY_H_
-#define MANTID_KERNEL_MATRIXPROPERTY_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -51,5 +50,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_MATRIXPROPERTY_H_
diff --git a/Framework/Kernel/inc/MantidKernel/Memory.h b/Framework/Kernel/inc/MantidKernel/Memory.h
index 384ee3fe158..8e6d98c07a0 100644
--- a/Framework/Kernel/inc/MantidKernel/Memory.h
+++ b/Framework/Kernel/inc/MantidKernel/Memory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MEMORY_H_
-#define MANTID_KERNEL_MEMORY_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -69,5 +68,3 @@ template <typename TYPE> std::string memToString(const TYPE mem_in_kiB);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNELMEMORY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/MersenneTwister.h b/Framework/Kernel/inc/MantidKernel/MersenneTwister.h
index 44e17445324..1217df7ca42 100644
--- a/Framework/Kernel/inc/MantidKernel/MersenneTwister.h
+++ b/Framework/Kernel/inc/MantidKernel/MersenneTwister.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MERSENNE_TWISTER_H_
-#define MANTID_KERNEL_MERSENNE_TWISTER_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -83,5 +82,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/MultiFileNameParser.h b/Framework/Kernel/inc/MantidKernel/MultiFileNameParser.h
index 6336aa760f6..74be41f6d53 100644
--- a/Framework/Kernel/inc/MantidKernel/MultiFileNameParser.h
+++ b/Framework/Kernel/inc/MantidKernel/MultiFileNameParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MULTIFILENAMEPARSER_H_
-#define MANTID_KERNEL_MULTIFILENAMEPARSER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -175,5 +174,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/MultiFileValidator.h b/Framework/Kernel/inc/MantidKernel/MultiFileValidator.h
index 4273eee31f7..9781f37456e 100644
--- a/Framework/Kernel/inc/MantidKernel/MultiFileValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/MultiFileValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MULTIFILEVALIDATOR_H_
-#define MANTID_KERNEL_MULTIFILEVALIDATOR_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -52,5 +51,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_MULTIFILEVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/MultiThreaded.h b/Framework/Kernel/inc/MantidKernel/MultiThreaded.h
index a05a85eabb9..21c847cefe1 100644
--- a/Framework/Kernel/inc/MantidKernel/MultiThreaded.h
+++ b/Framework/Kernel/inc/MantidKernel/MultiThreaded.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MULTITHREADED_H_
-#define MANTID_KERNEL_MULTITHREADED_H_
+#pragma once
 
 #include <atomic>
 #include <mutex>
@@ -240,5 +239,3 @@ inline void setMaxCoresToConfig() {
 #define PARALLEL_SECTION
 #define PRAGMA_OMP(expression)
 #endif //_OPENMP
-
-#endif // MANTID_KERNEL_MULTITHREADED_H_
diff --git a/Framework/Kernel/inc/MantidKernel/NDPseudoRandomNumberGenerator.h b/Framework/Kernel/inc/MantidKernel/NDPseudoRandomNumberGenerator.h
index 28c31eac380..c25319bdf6f 100644
--- a/Framework/Kernel/inc/MantidKernel/NDPseudoRandomNumberGenerator.h
+++ b/Framework/Kernel/inc/MantidKernel/NDPseudoRandomNumberGenerator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NDPSEUDORANDOMNUMBERGENERATOR_H_
-#define MANTID_KERNEL_NDPSEUDORANDOMNUMBERGENERATOR_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -140,5 +139,3 @@ void NDPseudoRandomNumberGenerator<SingleValueGenerator>::restore() {
 }
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_NDPSEUDORANDOMNUMBERGENERATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/NDRandomNumberGenerator.h b/Framework/Kernel/inc/MantidKernel/NDRandomNumberGenerator.h
index 6f506d80bc0..366c21f9212 100644
--- a/Framework/Kernel/inc/MantidKernel/NDRandomNumberGenerator.h
+++ b/Framework/Kernel/inc/MantidKernel/NDRandomNumberGenerator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NDRANDOMNUMBERGENERATOR_H_
-#define MANTID_KERNEL_NDRANDOMNUMBERGENERATOR_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -72,5 +71,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/NearestNeighbours.h b/Framework/Kernel/inc/MantidKernel/NearestNeighbours.h
index 4ad05308e11..a67c020321d 100644
--- a/Framework/Kernel/inc/MantidKernel/NearestNeighbours.h
+++ b/Framework/Kernel/inc/MantidKernel/NearestNeighbours.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NEARESTNEIGHBOURS_H_
-#define MANTID_KERNEL_NEARESTNEIGHBOURS_H_
+#pragma once
 
 #include "MantidKernel/ANN/ANN.h"
 #include "MantidKernel/DllConfig.h"
@@ -178,5 +177,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/NetworkProxy.h b/Framework/Kernel/inc/MantidKernel/NetworkProxy.h
index 515096e45c7..ce7b55dd28d 100644
--- a/Framework/Kernel/inc/MantidKernel/NetworkProxy.h
+++ b/Framework/Kernel/inc/MantidKernel/NetworkProxy.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NETWORKPROXY_H_
-#define MANTID_KERNEL_NETWORKPROXY_H_
+#pragma once
 
 #include "MantidKernel/Logger.h"
 #include "MantidKernel/ProxyInfo.h"
@@ -34,5 +33,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_NETWORKPROXY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/NeutronAtom.h b/Framework/Kernel/inc/MantidKernel/NeutronAtom.h
index 7e811695e0a..b85ce97063a 100644
--- a/Framework/Kernel/inc/MantidKernel/NeutronAtom.h
+++ b/Framework/Kernel/inc/MantidKernel/NeutronAtom.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NEUTRONATOM_H_
-#define MANTID_KERNEL_NEUTRONATOM_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Include
@@ -113,5 +112,3 @@ MANTID_KERNEL_DLL void calculateScatteringLengths(NeutronAtom &atom);
 
 } // Namespace PhysicalConstants
 } // Namespace Mantid
-
-#endif /* NEUTRONATOM_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/NexusDescriptor.h b/Framework/Kernel/inc/MantidKernel/NexusDescriptor.h
index a5e7bb29e2e..a58ea0c36c2 100644
--- a/Framework/Kernel/inc/MantidKernel/NexusDescriptor.h
+++ b/Framework/Kernel/inc/MantidKernel/NexusDescriptor.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NEXUSDESCRIPTOR_H_
-#define MANTID_KERNEL_NEXUSDESCRIPTOR_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -116,5 +115,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_HIERARCHICALFILEDESCRIPTOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/NullValidator.h b/Framework/Kernel/inc/MantidKernel/NullValidator.h
index f9b28521391..c44fbe0f49e 100644
--- a/Framework/Kernel/inc/MantidKernel/NullValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/NullValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NULLVALIDATOR_H_
-#define MANTID_KERNEL_NULLVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/IValidator.h"
 
@@ -28,5 +27,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_NULLVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/OptionalBool.h b/Framework/Kernel/inc/MantidKernel/OptionalBool.h
index f27b0f45680..6ae3643a174 100644
--- a/Framework/Kernel/inc/MantidKernel/OptionalBool.h
+++ b/Framework/Kernel/inc/MantidKernel/OptionalBool.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_OPTIONALBOOL_H_
-#define MANTID_KERNEL_OPTIONALBOOL_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <iosfwd>
@@ -58,5 +57,3 @@ MANTID_KERNEL_DLL ::Json::Value encodeAsJson(const OptionalBool &);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_OPTIONALBOOL_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ParaViewVersion.h b/Framework/Kernel/inc/MantidKernel/ParaViewVersion.h
index ee904132f9d..74f31700ba9 100644
--- a/Framework/Kernel/inc/MantidKernel/ParaViewVersion.h
+++ b/Framework/Kernel/inc/MantidKernel/ParaViewVersion.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PARAVIEW_VERSION_H_
-#define MANTID_KERNEL_PARAVIEW_VERSION_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -28,5 +27,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PARAVIEW_VERSION_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/PhysicalConstants.h b/Framework/Kernel/inc/MantidKernel/PhysicalConstants.h
index 346a93a270f..a7a23be643b 100644
--- a/Framework/Kernel/inc/MantidKernel/PhysicalConstants.h
+++ b/Framework/Kernel/inc/MantidKernel/PhysicalConstants.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_PHYSICALCONSTANTS_H_
-#define MANTID_PHYSICALCONSTANTS_H_
+#pragma once
 
 #include <cmath>
 
@@ -90,5 +89,3 @@ static constexpr double MuonGyromagneticRatio = 0.01355342;
 
 } // namespace PhysicalConstants
 } // namespace Mantid
-
-#endif /*MANTID_PHYSICALCONSTANTS_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PrecompiledHeader.h b/Framework/Kernel/inc/MantidKernel/PrecompiledHeader.h
index df177101ad9..130209d1919 100644
--- a/Framework/Kernel/inc/MantidKernel/PrecompiledHeader.h
+++ b/Framework/Kernel/inc/MantidKernel/PrecompiledHeader.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PRECOMPILEDHEADER_H_
-#define MANTID_KERNEL_PRECOMPILEDHEADER_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 
@@ -39,5 +38,3 @@
 #include <nexus/NeXusFile.hpp>
 #include <nexus/NeXusException.hpp>
 // clang-format on
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/ProgressBase.h b/Framework/Kernel/inc/MantidKernel/ProgressBase.h
index eddc09d95b8..6bd788f28b5 100644
--- a/Framework/Kernel/inc/MantidKernel/ProgressBase.h
+++ b/Framework/Kernel/inc/MantidKernel/ProgressBase.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROGRESSBASE_H_
-#define MANTID_KERNEL_PROGRESSBASE_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -95,5 +94,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PROGRESSBASE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Property.h b/Framework/Kernel/inc/MantidKernel/Property.h
index 2727e51b40d..13c601faf78 100644
--- a/Framework/Kernel/inc/MantidKernel/Property.h
+++ b/Framework/Kernel/inc/MantidKernel/Property.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTY_H_
-#define MANTID_KERNEL_PROPERTY_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -259,5 +258,3 @@ MANTID_KERNEL_DLL std::string getUnmangledTypeName(const std::type_info &type);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_PROPERTY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyHelper.h b/Framework/Kernel/inc/MantidKernel/PropertyHelper.h
index 161e8574361..bebd0dc1e2e 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyHelper.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYHELPER_H_
-#define MANTID_KERNEL_PROPERTYHELPER_H_
+#pragma once
 
 #ifndef Q_MOC_RUN
 #include <boost/lexical_cast.hpp>
@@ -378,5 +377,3 @@ inline std::vector<std::string> determineAllowedValues(const OptionalBool &,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PROPERTYHELPER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyHistory.h b/Framework/Kernel/inc/MantidKernel/PropertyHistory.h
index 60be33fbcc6..bf21d6f9d23 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyHistory.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyHistory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYHISTORY_H_
-#define MANTID_KERNEL_PROPERTYHISTORY_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -90,5 +89,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_PROPERTYHISTORY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyManager.h b/Framework/Kernel/inc/MantidKernel/PropertyManager.h
index 62f4ba0e277..b7d4c451c0c 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyManager.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyManager.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGER_H_
-#define MANTID_KERNEL_PROPERTYMANAGER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -140,5 +139,3 @@ MANTID_KERNEL_DLL ::Json::Value encodeAsJson(const PropertyManager &propMgr);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_PROPERTYMANAGER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyManagerDataService.h b/Framework/Kernel/inc/MantidKernel/PropertyManagerDataService.h
index 319e1ebd837..f4ddf8f162a 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyManagerDataService.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyManagerDataService.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGERDATASERVICE_
-#define MANTID_KERNEL_PROPERTYMANAGERDATASERVICE_
+#pragma once
 
 #include "MantidKernel/DataService.h"
 #include "MantidKernel/DllConfig.h"
@@ -42,5 +41,4 @@ using PropertyManagerDataService =
     Mantid::Kernel::SingletonHolder<PropertyManagerDataServiceImpl>;
 
 } // Namespace Kernel
-} // Namespace Mantid
-#endif /*MANTID_KERNEL_PROPERTYMANAGERDATASERVICE_*/
+} // Namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyManagerOwner.h b/Framework/Kernel/inc/MantidKernel/PropertyManagerOwner.h
index e8e8bad843c..e6073af8edc 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyManagerOwner.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyManagerOwner.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGEROWNER_H_
-#define MANTID_KERNEL_PROPERTYMANAGEROWNER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -127,5 +126,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_PROPERTYMANAGEROWNER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyManagerProperty.h b/Framework/Kernel/inc/MantidKernel/PropertyManagerProperty.h
index 45787bfd820..8971f3e2277 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyManagerProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyManagerProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGERPROPERTY_H_
-#define MANTID_KERNEL_PROPERTYMANAGERPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/PropertyManager_fwd.h"
 #include "MantidKernel/PropertyWithValue.h"
@@ -43,5 +42,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PROPERTYMANAGERPROPERTY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyManager_fwd.h b/Framework/Kernel/inc/MantidKernel/PropertyManager_fwd.h
index 3f7f06b8896..0616c83cba9 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyManager_fwd.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyManager_fwd.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGER_FWD_H
-#define MANTID_KERNEL_PROPERTYMANAGER_FWD_H
+#pragma once
 
 #include <boost/shared_ptr.hpp>
 #include <memory>
@@ -29,5 +28,3 @@ using PropertyManager_const_uptr = std::unique_ptr<const PropertyManager>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_PROPERTYMANAGER_FWD_H
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyNexus.h b/Framework/Kernel/inc/MantidKernel/PropertyNexus.h
index 9a05a886b28..bdb99f445c6 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyNexus.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyNexus.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYNEXUS_H_
-#define MANTID_KERNEL_PROPERTYNEXUS_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <memory>
@@ -35,5 +34,3 @@ DLLExport std::unique_ptr<Property> loadProperty(::NeXus::File *file,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PROPERTYNEXUS_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyWithValue.h b/Framework/Kernel/inc/MantidKernel/PropertyWithValue.h
index 074f0603994..6463e02ae5c 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyWithValue.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyWithValue.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYWITHVALUE_H_
-#define MANTID_KERNEL_PROPERTYWITHVALUE_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/Logger.h"
@@ -134,5 +133,3 @@ Logger PropertyWithValue<TYPE>::g_logger("PropertyWithValue");
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_PROPERTYWITHVALUE_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/PropertyWithValueJSON.h b/Framework/Kernel/inc/MantidKernel/PropertyWithValueJSON.h
index bb33edc4ece..eecfe6ec6f2 100644
--- a/Framework/Kernel/inc/MantidKernel/PropertyWithValueJSON.h
+++ b/Framework/Kernel/inc/MantidKernel/PropertyWithValueJSON.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYWITHVALUEJSON_H
-#define PROPERTYWITHVALUEJSON_H
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Exception.h"
@@ -167,5 +166,3 @@ Json::Value encodeAsJson(const Kernel::Matrix<ValueType> &) {
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // PROPERTYWITHVALUEJSON_H
diff --git a/Framework/Kernel/inc/MantidKernel/ProxyInfo.h b/Framework/Kernel/inc/MantidKernel/ProxyInfo.h
index f2eb181c85c..dcbda927744 100644
--- a/Framework/Kernel/inc/MantidKernel/ProxyInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/ProxyInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROXYINFO_H_
-#define MANTID_KERNEL_PROXYINFO_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <string>
@@ -34,5 +33,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PROXYINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/PseudoRandomNumberGenerator.h b/Framework/Kernel/inc/MantidKernel/PseudoRandomNumberGenerator.h
index 1f8de9505cc..11f3baae277 100644
--- a/Framework/Kernel/inc/MantidKernel/PseudoRandomNumberGenerator.h
+++ b/Framework/Kernel/inc/MantidKernel/PseudoRandomNumberGenerator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PSEUDORANDOMNUMBERGENERATOR_H_
-#define MANTID_KERNEL_PSEUDORANDOMNUMBERGENERATOR_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -57,5 +56,3 @@ public:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_PSEUDORANDOMNUMBERGENERATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/QuasiRandomNumberSequence.h b/Framework/Kernel/inc/MantidKernel/QuasiRandomNumberSequence.h
index 7ec99eed5dc..03eeb493e3e 100644
--- a/Framework/Kernel/inc/MantidKernel/QuasiRandomNumberSequence.h
+++ b/Framework/Kernel/inc/MantidKernel/QuasiRandomNumberSequence.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_QUASIRANDOMNUMBERSEQUENCE_H_
-#define MANTID_KERNEL_QUASIRANDOMNUMBERSEQUENCE_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -29,5 +28,3 @@ public:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_QUASIRANDOMNUMBERSEQUENCE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Quat.h b/Framework/Kernel/inc/MantidKernel/Quat.h
index 6c4d71c05b6..33b9fc63d29 100644
--- a/Framework/Kernel/inc/MantidKernel/Quat.h
+++ b/Framework/Kernel/inc/MantidKernel/Quat.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_QUAT_H_
-#define MANTID_KERNEL_QUAT_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -150,5 +149,3 @@ MANTID_KERNEL_DLL std::istream &operator>>(std::istream &, Quat &q);
 } // namespace Kernel
 
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_QUAT_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/ReadLock.h b/Framework/Kernel/inc/MantidKernel/ReadLock.h
index 3c568b1830b..c46d01bf3c7 100644
--- a/Framework/Kernel/inc/MantidKernel/ReadLock.h
+++ b/Framework/Kernel/inc/MantidKernel/ReadLock.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_READLOCK_H_
-#define MANTID_KERNEL_READLOCK_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -54,5 +53,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_READLOCK_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/RebinParamsValidator.h b/Framework/Kernel/inc/MantidKernel/RebinParamsValidator.h
index 100ca51fe89..6911160a0e3 100644
--- a/Framework/Kernel/inc/MantidKernel/RebinParamsValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/RebinParamsValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_REBINPARAMSVALIDATOR_H_
-#define MANTID_KERNEL_REBINPARAMSVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/TypedValidator.h"
 #include <vector>
@@ -31,5 +30,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_REBINPARAMSVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/RegexStrings.h b/Framework/Kernel/inc/MantidKernel/RegexStrings.h
index 333dc17ee19..63de2da7c4f 100644
--- a/Framework/Kernel/inc/MantidKernel/RegexStrings.h
+++ b/Framework/Kernel/inc/MantidKernel/RegexStrings.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef REGEXSUPPORT_H
-#define REGEXSUPPORT_H
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #ifndef Q_MOC_RUN
@@ -64,5 +63,4 @@ MANTID_KERNEL_DLL int findPattern(std::istream &, const boost::regex &,
 
 } // NAMESPACE Kernel
 
-} // NAMESPACE Mantid
-#endif
+} // NAMESPACE Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/RegistrationHelper.h b/Framework/Kernel/inc/MantidKernel/RegistrationHelper.h
index fe8486b0d22..331a364d7f8 100644
--- a/Framework/Kernel/inc/MantidKernel/RegistrationHelper.h
+++ b/Framework/Kernel/inc/MantidKernel/RegistrationHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_REGISTRATIONHELPER_H_
-#define MANTID_KERNEL_REGISTRATIONHELPER_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 
@@ -27,5 +26,3 @@ public:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_REGISTRATIONHELPER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/RemoteJobManager.h b/Framework/Kernel/inc/MantidKernel/RemoteJobManager.h
index 90361b22345..2de8a3fb36b 100644
--- a/Framework/Kernel/inc/MantidKernel/RemoteJobManager.h
+++ b/Framework/Kernel/inc/MantidKernel/RemoteJobManager.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef REMOTEJOBMANAGER_H
-#define REMOTEJOBMANAGER_H
+#pragma once
 
 #include <iosfwd>
 #include <map>
@@ -112,5 +111,3 @@ private:
 
 } // end namespace Kernel
 } // end namespace Mantid
-
-#endif // REMOTEJOBMANAGER_H
diff --git a/Framework/Kernel/inc/MantidKernel/SimpleJSON.h b/Framework/Kernel/inc/MantidKernel/SimpleJSON.h
index e5e1f1ac4de..3a4da789475 100644
--- a/Framework/Kernel/inc/MantidKernel/SimpleJSON.h
+++ b/Framework/Kernel/inc/MantidKernel/SimpleJSON.h
@@ -17,8 +17,7 @@
   RGM - 23 July 2012
   ******************************************************************/
 
-#ifndef SIMPLEJSON_H
-#define SIMPLEJSON_H
+#pragma once
 
 #include <istream>
 #include <map>
@@ -121,5 +120,3 @@ class DLLExport JSONParseException : public JSONException {
 public:
   JSONParseException(const std::string &msg) : JSONException(msg) {}
 };
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/SingletonHolder.h b/Framework/Kernel/inc/MantidKernel/SingletonHolder.h
index 49892b81b88..51ffda22895 100644
--- a/Framework/Kernel/inc/MantidKernel/SingletonHolder.h
+++ b/Framework/Kernel/inc/MantidKernel/SingletonHolder.h
@@ -1,5 +1,4 @@
-#ifndef MANTID_KERNEL_SINGLETON_HOLDER_H
-#define MANTID_KERNEL_SINGLETON_HOLDER_H
+#pragma once
 
 ////////////////////////////////////////////////////////////////////////////////
 // The Loki Library
@@ -111,5 +110,3 @@ __declspec(noinline)
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // SINGLETON_HOLDER_H
diff --git a/Framework/Kernel/inc/MantidKernel/SobolSequence.h b/Framework/Kernel/inc/MantidKernel/SobolSequence.h
index 88d8c87c6b9..29dca66c682 100644
--- a/Framework/Kernel/inc/MantidKernel/SobolSequence.h
+++ b/Framework/Kernel/inc/MantidKernel/SobolSequence.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SOBOLSEQUENCE_H_
-#define MANTID_KERNEL_SOBOLSEQUENCE_H_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -63,5 +62,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_SOBOLSEQUENCE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/SpecialCoordinateSystem.h b/Framework/Kernel/inc/MantidKernel/SpecialCoordinateSystem.h
index dc8cf2359ef..a5bae38eef4 100644
--- a/Framework/Kernel/inc/MantidKernel/SpecialCoordinateSystem.h
+++ b/Framework/Kernel/inc/MantidKernel/SpecialCoordinateSystem.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SpecialCoordinateSystem_H_
-#define MANTID_KERNEL_SpecialCoordinateSystem_H_
+#pragma once
 
 namespace Mantid {
 namespace Kernel {
@@ -20,5 +19,3 @@ enum SpecialCoordinateSystem {
 }; // Do NOT alter existing values
 } // namespace Kernel
 } // namespace Mantid
-
-#endif
diff --git a/Framework/Kernel/inc/MantidKernel/StartsWithValidator.h b/Framework/Kernel/inc/MantidKernel/StartsWithValidator.h
index 82f164ca807..d2493636617 100644
--- a/Framework/Kernel/inc/MantidKernel/StartsWithValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/StartsWithValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STARTSWITHVALIDATOR_H_
-#define MANTID_KERNEL_STARTSWITHVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/IValidator.h"
 #include "MantidKernel/ListValidator.h"
@@ -41,5 +40,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_STARTSWITHVALIDATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/Statistics.h b/Framework/Kernel/inc/MantidKernel/Statistics.h
index e337e608b57..49b4538486e 100644
--- a/Framework/Kernel/inc/MantidKernel/Statistics.h
+++ b/Framework/Kernel/inc/MantidKernel/Statistics.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STATISTICS_H_
-#define MANTID_KERNEL_STATISTICS_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <vector>
@@ -101,5 +100,4 @@ std::vector<double> getMomentsAboutMean(const std::vector<TYPE> &x,
                                         const std::vector<TYPE> &y,
                                         const int maxMoment = 3);
 } // namespace Kernel
-} // namespace Mantid
-#endif /* STATISTICS_H_ */
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/StdoutChannel.h b/Framework/Kernel/inc/MantidKernel/StdoutChannel.h
index 6e21809c9e9..e50c9cbeceb 100644
--- a/Framework/Kernel/inc/MantidKernel/StdoutChannel.h
+++ b/Framework/Kernel/inc/MantidKernel/StdoutChannel.h
@@ -15,8 +15,7 @@
 //
 //
 
-#ifndef STDOUTCHANNEL_H
-#define STDOUTCHANNEL_H
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <Poco/ConsoleChannel.h>
@@ -26,5 +25,4 @@ public:
   /// Constructor for StdChannel
   StdoutChannel();
 };
-} // namespace Poco
-#endif // STDOUTCHANNEL_H
+} // namespace Poco
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/StringContainsValidator.h b/Framework/Kernel/inc/MantidKernel/StringContainsValidator.h
index 2c4567d27ec..96ef1be52a5 100644
--- a/Framework/Kernel/inc/MantidKernel/StringContainsValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/StringContainsValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STRINGCONTAINSVALIDATOR_H_
-#define MANTID_KERNEL_STRINGCONTAINSVALIDATOR_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/TypedValidator.h"
@@ -42,5 +41,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_STRINGCONTAINSVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/StringTokenizer.h b/Framework/Kernel/inc/MantidKernel/StringTokenizer.h
index e33187ff7a9..d7b2dae0306 100644
--- a/Framework/Kernel/inc/MantidKernel/StringTokenizer.h
+++ b/Framework/Kernel/inc/MantidKernel/StringTokenizer.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STRINGTOKENIZER_H_
-#define MANTID_KERNEL_STRINGTOKENIZER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -124,5 +123,3 @@ private:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* StringTokenizer_h */
diff --git a/Framework/Kernel/inc/MantidKernel/Strings.h b/Framework/Kernel/inc/MantidKernel/Strings.h
index c6eb4485f06..ec78735d147 100644
--- a/Framework/Kernel/inc/MantidKernel/Strings.h
+++ b/Framework/Kernel/inc/MantidKernel/Strings.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STRINGS_H
-#define MANTID_KERNEL_STRINGS_H
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -466,5 +465,3 @@ MANTID_KERNEL_DLL std::istream &extractToEOL(std::istream &is,
 } // NAMESPACE Kernel
 
 } // NAMESPACE Mantid
-
-#endif // MANTID_KERNEL_STRINGS_H
diff --git a/Framework/Kernel/inc/MantidKernel/System.h b/Framework/Kernel/inc/MantidKernel/System.h
index a14f1551dee..98a89858b11 100644
--- a/Framework/Kernel/inc/MantidKernel/System.h
+++ b/Framework/Kernel/inc/MantidKernel/System.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SYSTEM_H_
-#define MANTID_KERNEL_SYSTEM_H_
+#pragma once
 
 /*******************************************************************************
  *                      READ THIS!! (AND THEN READ IT AGAIN)
@@ -82,5 +81,3 @@
  */
 #include <cstddef>
 #include <cstdint>
-
-#endif /*MANTID_KERNEL_SYSTEM_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/Task.h b/Framework/Kernel/inc/MantidKernel/Task.h
index b276a044306..eaaebaee989 100644
--- a/Framework/Kernel/inc/MantidKernel/Task.h
+++ b/Framework/Kernel/inc/MantidKernel/Task.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TASK_H_
-#define MANTID_KERNEL_TASK_H_
+#pragma once
 
 #ifndef Q_MOC_RUN
 #include <boost/shared_ptr.hpp>
@@ -88,5 +87,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_TASK_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/TestChannel.h b/Framework/Kernel/inc/MantidKernel/TestChannel.h
index 43fe93ccb2f..a2ddcca7ad9 100644
--- a/Framework/Kernel/inc/MantidKernel/TestChannel.h
+++ b/Framework/Kernel/inc/MantidKernel/TestChannel.h
@@ -31,8 +31,7 @@
 // DEALINGS IN THE SOFTWARE.
 //
 
-#ifndef TESTCHANNEL_H_
-#define TESTCHANNEL_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -53,5 +52,3 @@ private:
   MsgList _msgList;
 };
 } // namespace Mantid
-
-#endif // TESTCHANNEL_H_
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadPool.h b/Framework/Kernel/inc/MantidKernel/ThreadPool.h
index 25810709c2b..b6c308dc24e 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadPool.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadPool.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef THREADPOOL_H_
-#define THREADPOOL_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/ThreadScheduler.h"
@@ -86,5 +85,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* THREADPOOL_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadPoolRunnable.h b/Framework/Kernel/inc/MantidKernel/ThreadPoolRunnable.h
index 965a1fc928b..fc610a2d8de 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadPoolRunnable.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadPoolRunnable.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADPOOLRUNNABLE_H_
-#define MANTID_KERNEL_THREADPOOLRUNNABLE_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <Poco/Runnable.h>
@@ -50,5 +49,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_THREADPOOLRUNNABLE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadSafeLogStream.h b/Framework/Kernel/inc/MantidKernel/ThreadSafeLogStream.h
index f74f852c4a8..bb55e3c00f1 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadSafeLogStream.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadSafeLogStream.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADSAFELOGSTREAM
-#define MANTID_KERNEL_THREADSAFELOGSTREAM
+#pragma once
 
 //--------------------------------------------
 // Includes
@@ -147,5 +146,3 @@ public:
 };
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_THREADSAFELOGSTREAM
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h b/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
index e3039773916..1c69c0cb4d0 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef THREADSCHEDULER_H_
-#define THREADSCHEDULER_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/SingletonHolder.h"
@@ -292,5 +291,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* THREADSCHEDULER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h b/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
index 3dbb335ac75..55552a776c4 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADSCHEDULERMUTEXES_H_
-#define MANTID_KERNEL_THREADSCHEDULERMUTEXES_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/ThreadScheduler.h"
@@ -180,5 +179,3 @@ protected:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_THREADSCHEDULERMUTEXES_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/TimeSeriesProperty.h b/Framework/Kernel/inc/MantidKernel/TimeSeriesProperty.h
index 91a34719d8c..122c2c915dd 100644
--- a/Framework/Kernel/inc/MantidKernel/TimeSeriesProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/TimeSeriesProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TIMESERIESPROPERTY_H_
-#define MANTID_KERNEL_TIMESERIESPROPERTY_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -361,5 +360,3 @@ filterByStatistic(TimeSeriesProperty<double> const *const propertyToFilter,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_TIMESERIESPROPERTY_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/TimeSplitter.h b/Framework/Kernel/inc/MantidKernel/TimeSplitter.h
index c205aa2b055..9c5b4b5f5aa 100644
--- a/Framework/Kernel/inc/MantidKernel/TimeSplitter.h
+++ b/Framework/Kernel/inc/MantidKernel/TimeSplitter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TIMESPLITTER_H
-#define TIMESPLITTER_H
+#pragma once
 
 #include "MantidKernel/DateAndTime.h"
 
@@ -72,5 +71,3 @@ MANTID_KERNEL_DLL TimeSplitterType operator~(const TimeSplitterType &a);
 
 } // Namespace Kernel
 } // Namespace Mantid
-
-#endif // TIMESPLITTER_H
diff --git a/Framework/Kernel/inc/MantidKernel/Timer.h b/Framework/Kernel/inc/MantidKernel/Timer.h
index db5c482d8d5..b7761466864 100644
--- a/Framework/Kernel/inc/MantidKernel/Timer.h
+++ b/Framework/Kernel/inc/MantidKernel/Timer.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TIMER_H_
-#define MANTID_KERNEL_TIMER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -41,5 +40,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &, const Timer &);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* TIMER_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Tolerance.h b/Framework/Kernel/inc/MantidKernel/Tolerance.h
index dd46e01b546..a946786da8e 100644
--- a/Framework/Kernel/inc/MantidKernel/Tolerance.h
+++ b/Framework/Kernel/inc/MantidKernel/Tolerance.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TOLERANCE_H_
-#define MANTID_KERNEL_TOLERANCE_H_
+#pragma once
 
 namespace Mantid {
 namespace Kernel {
@@ -14,5 +13,3 @@ constexpr double Tolerance = 1.0e-06;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_TOLERANCE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/TopicInfo.h b/Framework/Kernel/inc/MantidKernel/TopicInfo.h
index d378724fbcc..0085b71d9d9 100644
--- a/Framework/Kernel/inc/MantidKernel/TopicInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/TopicInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TOPICINFO_H_
-#define MANTID_KERNEL_TOPICINFO_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -48,5 +47,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &buffer,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_TOPICINFO_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/TypedValidator.h b/Framework/Kernel/inc/MantidKernel/TypedValidator.h
index 475b24e67e8..b8711a1da61 100644
--- a/Framework/Kernel/inc/MantidKernel/TypedValidator.h
+++ b/Framework/Kernel/inc/MantidKernel/TypedValidator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TYPEDVALIDATOR_H_
-#define MANTID_KERNEL_TYPEDVALIDATOR_H_
+#pragma once
 //----------------------------------------------------------------------
 // Includes
 //----------------------------------------------------------------------
@@ -148,5 +147,3 @@ const std::type_info &TypedValidator<boost::shared_ptr<T>>::m_dataitemTypeID =
 } // namespace Kernel
 /// @endcond
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_TYPEDVALIDATOR_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/Unit.h b/Framework/Kernel/inc/MantidKernel/Unit.h
index 0c19807e50b..d475f6889ae 100644
--- a/Framework/Kernel/inc/MantidKernel/Unit.h
+++ b/Framework/Kernel/inc/MantidKernel/Unit.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNIT_H_
-#define MANTID_KERNEL_UNIT_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -701,5 +700,3 @@ void timeConversionVector(std::vector<T> &vec, std::string input_unit,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_UNIT_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/UnitConversion.h b/Framework/Kernel/inc/MantidKernel/UnitConversion.h
index d718491a730..0f99aa63508 100644
--- a/Framework/Kernel/inc/MantidKernel/UnitConversion.h
+++ b/Framework/Kernel/inc/MantidKernel/UnitConversion.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITCONVERSION_H_
-#define MANTID_KERNEL_UNITCONVERSION_H_
+#pragma once
 
 #include "MantidKernel/DeltaEMode.h"
 #include "MantidKernel/DllConfig.h"
@@ -50,5 +49,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_UNITCONVERSION_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/UnitFactory.h b/Framework/Kernel/inc/MantidKernel/UnitFactory.h
index 553bd44d0c5..f59e2d8178f 100644
--- a/Framework/Kernel/inc/MantidKernel/UnitFactory.h
+++ b/Framework/Kernel/inc/MantidKernel/UnitFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITFACTORYIMPL_H_
-#define MANTID_KERNEL_UNITFACTORYIMPL_H_
+#pragma once
 
 /* Used to register unit classes into the factory. creates a global object in an
  * anonymous namespace. The object itself does nothing, but the comma operator
@@ -86,5 +85,3 @@ using UnitFactory = SingletonHolder<UnitFactoryImpl>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_UNITFACTORYIMPL_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/UnitLabel.h b/Framework/Kernel/inc/MantidKernel/UnitLabel.h
index 40864d91b4f..fc02005ceef 100644
--- a/Framework/Kernel/inc/MantidKernel/UnitLabel.h
+++ b/Framework/Kernel/inc/MantidKernel/UnitLabel.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITLABEL_H_
-#define MANTID_KERNEL_UNITLABEL_H_
+#pragma once
 /**
   Define a
 */
@@ -76,5 +75,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_UNITLABEL_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/UnitLabelTypes.h b/Framework/Kernel/inc/MantidKernel/UnitLabelTypes.h
index 4fe455095c1..9f4fc5fc107 100644
--- a/Framework/Kernel/inc/MantidKernel/UnitLabelTypes.h
+++ b/Framework/Kernel/inc/MantidKernel/UnitLabelTypes.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITLABELTYPES_H_
-#define MANTID_KERNEL_UNITLABELTYPES_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -50,5 +49,3 @@ public:
 } // namespace Units
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_UNITLABELTYPES_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/UsageService.h b/Framework/Kernel/inc/MantidKernel/UsageService.h
index 7094bb1dd4f..f4e524aacd6 100644
--- a/Framework/Kernel/inc/MantidKernel/UsageService.h
+++ b/Framework/Kernel/inc/MantidKernel/UsageService.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_USAGESERVICE_H_
-#define MANTID_KERNEL_USAGESERVICE_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/SingletonHolder.h"
@@ -161,5 +160,3 @@ using UsageService = Mantid::Kernel::SingletonHolder<UsageServiceImpl>;
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_USAGESERVICE_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/UserCatalogInfo.h b/Framework/Kernel/inc/MantidKernel/UserCatalogInfo.h
index 06e3571330f..00858f6b4fb 100644
--- a/Framework/Kernel/inc/MantidKernel/UserCatalogInfo.h
+++ b/Framework/Kernel/inc/MantidKernel/UserCatalogInfo.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_USERCATALOGINFO_H_
-#define MANTID_KERNEL_USERCATALOGINFO_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/ICatalogInfo.h"
@@ -75,5 +74,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_USERCATALOGINFO_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/UserStringParser.h b/Framework/Kernel/inc/MantidKernel/UserStringParser.h
index 8666d7c44c6..58ecb9ca4d5 100644
--- a/Framework/Kernel/inc/MantidKernel/UserStringParser.h
+++ b/Framework/Kernel/inc/MantidKernel/UserStringParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_RANGESTRINGPARSER_H_
-#define MANTID_KERNEL_RANGESTRINGPARSER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -76,5 +75,4 @@ private:
                             const std::vector<std::string> &tokens);
 };
 } // namespace Kernel
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/Utils.h b/Framework/Kernel/inc/MantidKernel/Utils.h
index f682f37c004..6a56974d4af 100644
--- a/Framework/Kernel/inc/MantidKernel/Utils.h
+++ b/Framework/Kernel/inc/MantidKernel/Utils.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UTILS_H_
-#define MANTID_KERNEL_UTILS_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <cmath>
@@ -314,5 +313,3 @@ isNeighbourOfSubject(const size_t ndims, const size_t neighbour_linear_index,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_UTILS_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/V2D.h b/Framework/Kernel/inc/MantidKernel/V2D.h
index 574338449b7..a6659b5e528 100644
--- a/Framework/Kernel/inc/MantidKernel/V2D.h
+++ b/Framework/Kernel/inc/MantidKernel/V2D.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_V2D_H_
-#define MANTID_KERNEL_V2D_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -172,5 +171,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &, const V2D &);
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_V2D_H_
diff --git a/Framework/Kernel/inc/MantidKernel/V3D.h b/Framework/Kernel/inc/MantidKernel/V3D.h
index 301cb29e44e..58de6edb7fc 100644
--- a/Framework/Kernel/inc/MantidKernel/V3D.h
+++ b/Framework/Kernel/inc/MantidKernel/V3D.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_V3D_H_
-#define MANTID_KERNEL_V3D_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include "MantidKernel/Exception.h"
@@ -373,5 +372,3 @@ inline MANTID_KERNEL_DLL V3D normalize(V3D v) {
 
 } // Namespace Kernel
 } // Namespace Mantid
-
-#endif /*MANTID_KERNEL_V3D_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/VMD.h b/Framework/Kernel/inc/MantidKernel/VMD.h
index 7e43b465605..b22ea41f0ee 100644
--- a/Framework/Kernel/inc/MantidKernel/VMD.h
+++ b/Framework/Kernel/inc/MantidKernel/VMD.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VMD_H_
-#define MANTID_KERNEL_VMD_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 #include <string>
@@ -96,5 +95,3 @@ MANTID_KERNEL_DLL std::ostream &operator<<(std::ostream &,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_VMD_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/VectorHelper.h b/Framework/Kernel/inc/MantidKernel/VectorHelper.h
index 97b222db458..7530cbad9a9 100644
--- a/Framework/Kernel/inc/MantidKernel/VectorHelper.h
+++ b/Framework/Kernel/inc/MantidKernel/VectorHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VECTORHELPER_H_
-#define MANTID_KERNEL_VECTORHELPER_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -248,5 +247,3 @@ template <class T> struct SimpleAverage {
 } // namespace VectorHelper
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_VECTORHELPER_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/VisibleWhenProperty.h b/Framework/Kernel/inc/MantidKernel/VisibleWhenProperty.h
index e832d14191e..40b02627f7d 100644
--- a/Framework/Kernel/inc/MantidKernel/VisibleWhenProperty.h
+++ b/Framework/Kernel/inc/MantidKernel/VisibleWhenProperty.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VISIBLEWHENPROPERTY_H_
-#define MANTID_KERNEL_VISIBLEWHENPROPERTY_H_
+#pragma once
 
 #include "MantidKernel/EnabledWhenProperty.h"
 #include "MantidKernel/System.h"
@@ -59,5 +58,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_VISIBLEWHENPROPERTY_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/WarningSuppressions.h b/Framework/Kernel/inc/MantidKernel/WarningSuppressions.h
index 1ffd322d9e5..fd9a5d3725e 100644
--- a/Framework/Kernel/inc/MantidKernel/WarningSuppressions.h
+++ b/Framework/Kernel/inc/MantidKernel/WarningSuppressions.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_WARNINGSUPPRESSIONS_H_
-#define MANTID_KERNEL_WARNINGSUPPRESSIONS_H_
+#pragma once
 
 /*  A system-wide file to contain, e.g., useful system-dependent macros
     for suppressing compiler warnings.
@@ -109,5 +108,3 @@
 #else
 #define GNU_UNUSED_FUNCTION
 #endif
-
-#endif /*MANTID_KERNEL_WARNINGSUPPRESSIONS_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/WriteLock.h b/Framework/Kernel/inc/MantidKernel/WriteLock.h
index eeebc718445..1d571f67a45 100644
--- a/Framework/Kernel/inc/MantidKernel/WriteLock.h
+++ b/Framework/Kernel/inc/MantidKernel/WriteLock.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_WRITELOCK_H_
-#define MANTID_KERNEL_WRITELOCK_H_
+#pragma once
 
 #include "MantidKernel/DllConfig.h"
 
@@ -58,5 +57,3 @@ private:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /* MANTID_KERNEL_WRITELOCK_H_ */
diff --git a/Framework/Kernel/inc/MantidKernel/XMLInstantiator.h b/Framework/Kernel/inc/MantidKernel/XMLInstantiator.h
index 66cb9517811..02cd2e50cd3 100644
--- a/Framework/Kernel/inc/MantidKernel/XMLInstantiator.h
+++ b/Framework/Kernel/inc/MantidKernel/XMLInstantiator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_XMLINSTANTIATOR_H_
-#define MANTID_KERNEL_XMLINSTANTIATOR_H_
+#pragma once
 
 #ifndef Q_MOC_RUN
 #include <boost/shared_ptr.hpp>
@@ -94,5 +93,3 @@ public:
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif /*MANTID_KERNEL_XMLINSTANTIATOR_H_*/
diff --git a/Framework/Kernel/inc/MantidKernel/cow_ptr.h b/Framework/Kernel/inc/MantidKernel/cow_ptr.h
index 16ed9e9e0b0..f92f81b0a7c 100644
--- a/Framework/Kernel/inc/MantidKernel/cow_ptr.h
+++ b/Framework/Kernel/inc/MantidKernel/cow_ptr.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTIDKERNEL_COW_PTR_H
-#define MANTIDKERNEL_COW_PTR_H
+#pragma once
 
 #include "MultiThreaded.h"
 
@@ -193,5 +192,3 @@ using MantidVec = std::vector<double>;
 using MantidVecPtr = Kernel::cow_ptr<MantidVec>;
 
 } // NAMESPACE Mantid
-
-#endif // MANTIDKERNEL_COW_PTR_H
diff --git a/Framework/Kernel/inc/MantidKernel/make_cow.h b/Framework/Kernel/inc/MantidKernel/make_cow.h
index e1864cb2f68..cf4c7d79a8c 100644
--- a/Framework/Kernel/inc/MantidKernel/make_cow.h
+++ b/Framework/Kernel/inc/MantidKernel/make_cow.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef Mantid_make_cow_h
-#define Mantid_make_cow_h
+#pragma once
 
 #include "MantidKernel/cow_ptr.h"
 #include <boost/make_shared.hpp>
@@ -23,5 +22,4 @@ template <class T, class... Args> inline cow_ptr<T> make_cow(Args &&... args) {
 }
 
 } // namespace Kernel
-} // namespace Mantid
-#endif // Mantid_cow_unique_h
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/Kernel/inc/MantidKernel/normal_distribution.h b/Framework/Kernel/inc/MantidKernel/normal_distribution.h
index ba68e39da3e..7c4bd50b4ab 100644
--- a/Framework/Kernel/inc/MantidKernel/normal_distribution.h
+++ b/Framework/Kernel/inc/MantidKernel/normal_distribution.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NORMAL_DISRIBUTION_H_
-#define MANTID_KERNEL_NORMAL_DISRIBUTION_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/WarningSuppressions.h"
@@ -227,5 +226,3 @@ operator>>(std::basic_istream<_CharT, _Traits> &__is,
 
 } // namespace Kernel
 } // namespace Mantid
-
-#endif // MANTID_KERNEL_NORMAL_DISRIBUTION_H_
diff --git a/Framework/Kernel/inc/MantidKernel/uniform_int_distribution.h b/Framework/Kernel/inc/MantidKernel/uniform_int_distribution.h
index 13cb2489ee8..2fdd3a9af10 100644
--- a/Framework/Kernel/inc/MantidKernel/uniform_int_distribution.h
+++ b/Framework/Kernel/inc/MantidKernel/uniform_int_distribution.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNIFORM_INT_DISRIBUTION_H_
-#define MANTID_KERNEL_UNIFORM_INT_DISRIBUTION_H_
+#pragma once
 
 #include <limits>
 #include <random>
@@ -324,5 +323,3 @@ uniform_int_distribution<_IntType>::operator()(_URNG &__g,
 #undef __CHAR_BIT__
 #undef _MANTID_CHAR_BIT_DEFINED_HERE
 #endif
-
-#endif // MANTID_KERNEL_UNIFORM_INT_DISRIBUTION_H_
diff --git a/Framework/Kernel/src/ANN/bd_tree.h b/Framework/Kernel/src/ANN/bd_tree.h
index 10ba69c5a0b..e11dc694315 100644
--- a/Framework/Kernel/src/ANN/bd_tree.h
+++ b/Framework/Kernel/src/ANN/bd_tree.h
@@ -24,8 +24,7 @@
 //		Changed IN, OUT to ANN_IN, ANN_OUT
 //----------------------------------------------------------------------
 
-#ifndef ANN_bd_tree_H
-#define ANN_bd_tree_H
+#pragma once
 
 #include "MantidKernel/ANN/ANNx.h" // all ANN includes
 #include "kd_tree.h"               // kd-tree includes
@@ -96,5 +95,3 @@ public:
   void ann_pri_search(ANNdist) override; // priority search
   void ann_FR_search(ANNdist) override;  // fixed-radius search
 };
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_fix_rad_search.h b/Framework/Kernel/src/ANN/kd_fix_rad_search.h
index e3022640bd0..20cb2b49657 100644
--- a/Framework/Kernel/src/ANN/kd_fix_rad_search.h
+++ b/Framework/Kernel/src/ANN/kd_fix_rad_search.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef ANN_kd_fix_rad_search_H
-#define ANN_kd_fix_rad_search_H
+#pragma once
 
 #include "kd_tree.h"    // kd-tree declarations
 #include "kd_util.h"    // kd-tree utilities
@@ -40,5 +39,3 @@
 //----------------------------------------------------------------------
 
 extern ANNpoint ANNkdFRQ; // query point (static copy)
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_pr_search.h b/Framework/Kernel/src/ANN/kd_pr_search.h
index e0aff1c1a4a..8434611d84c 100644
--- a/Framework/Kernel/src/ANN/kd_pr_search.h
+++ b/Framework/Kernel/src/ANN/kd_pr_search.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef ANN_kd_pr_search_H
-#define ANN_kd_pr_search_H
+#pragma once
 
 #include "kd_tree.h"    // kd-tree declarations
 #include "kd_util.h"    // kd-tree utilities
@@ -45,5 +44,3 @@ extern double ANNprMaxErr;      // max tolerable squared error
 extern ANNpointArray ANNprPts;  // the points
 extern ANNpr_queue *ANNprBoxPQ; // priority queue for boxes
 extern ANNmin_k *ANNprPointMK;  // set of k closest points
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_search.h b/Framework/Kernel/src/ANN/kd_search.h
index c71cbf72370..164f5358565 100644
--- a/Framework/Kernel/src/ANN/kd_search.h
+++ b/Framework/Kernel/src/ANN/kd_search.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef ANN_kd_search_H
-#define ANN_kd_search_H
+#pragma once
 
 #include "kd_tree.h"    // kd-tree declarations
 #include "kd_util.h"    // kd-tree utilities
@@ -44,5 +43,3 @@ extern double ANNkdMaxErr;     // max tolerable squared error
 extern ANNpointArray ANNkdPts; // the points (static copy)
 extern ANNmin_k *ANNkdPointMK; // set of k closest points
 extern int ANNptsVisited;      // number of points visited
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_split.h b/Framework/Kernel/src/ANN/kd_split.h
index 716244d10e4..ccb92c041bf 100644
--- a/Framework/Kernel/src/ANN/kd_split.h
+++ b/Framework/Kernel/src/ANN/kd_split.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef ANN_KD_SPLIT_H
-#define ANN_KD_SPLIT_H
+#pragma once
 
 #include "kd_tree.h" // kd-tree definitions
 
@@ -81,5 +80,3 @@ void sl_fair_split(          // sliding fair-split kd-splitter
     int &cut_dim,            // cutting dimension (returned)
     ANNcoord &cut_val,       // cutting value (returned)
     int &n_lo);              // num of points on low side (returned)
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_tree.h b/Framework/Kernel/src/ANN/kd_tree.h
index 960b5d00c81..c48db262978 100644
--- a/Framework/Kernel/src/ANN/kd_tree.h
+++ b/Framework/Kernel/src/ANN/kd_tree.h
@@ -24,8 +24,7 @@
 //		Added fixed radius kNN search
 //----------------------------------------------------------------------
 
-#ifndef ANN_kd_tree_H
-#define ANN_kd_tree_H
+#pragma once
 
 #include "MantidKernel/ANN/ANNx.h" // all ANN includes
 
@@ -187,5 +186,3 @@ ANNkd_ptr rkd_tree(           // recursive construction of kd-tree
     int bsp,                  // bucket space
     ANNorthRect &bnd_box,     // bounding box for current node
     ANNkd_splitter splitter); // splitting routine
-
-#endif
diff --git a/Framework/Kernel/src/ANN/kd_util.h b/Framework/Kernel/src/ANN/kd_util.h
index 19414312446..b67496970fb 100644
--- a/Framework/Kernel/src/ANN/kd_util.h
+++ b/Framework/Kernel/src/ANN/kd_util.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef ANN_kd_util_H
-#define ANN_kd_util_H
+#pragma once
 
 #include "kd_tree.h" // kd-tree declarations
 
@@ -120,5 +119,3 @@ void annBnds2Box(               // convert bounds to inner box
     int n_bnds,                 // number of bounds
     ANNorthHSArray bnds,        // bounds array
     ANNorthRect &inner_box);    // inner box (returned)
-
-#endif
diff --git a/Framework/Kernel/src/ANN/pr_queue.h b/Framework/Kernel/src/ANN/pr_queue.h
index ea087790515..425572f5593 100644
--- a/Framework/Kernel/src/ANN/pr_queue.h
+++ b/Framework/Kernel/src/ANN/pr_queue.h
@@ -23,8 +23,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef PR_QUEUE_H
-#define PR_QUEUE_H
+#pragma once
 
 #include "MantidKernel/ANN/ANNperf.h" // performance evaluation
 #include "MantidKernel/ANN/ANNx.h"    // all ANN includes
@@ -139,5 +138,3 @@ public:
     pq[p] = pq[n + 1]; // insert last item in proper place
   }
 };
-
-#endif
diff --git a/Framework/Kernel/src/ANN/pr_queue_k.h b/Framework/Kernel/src/ANN/pr_queue_k.h
index e321f1ac2a6..1a5e04e67b1 100644
--- a/Framework/Kernel/src/ANN/pr_queue_k.h
+++ b/Framework/Kernel/src/ANN/pr_queue_k.h
@@ -22,8 +22,7 @@
 //		Initial release
 //----------------------------------------------------------------------
 
-#ifndef PR_QUEUE_K_H
-#define PR_QUEUE_K_H
+#pragma once
 
 #include "MantidKernel/ANN/ANNperf.h" // performance evaluation
 #include "MantidKernel/ANN/ANNx.h"    // all ANN includes
@@ -125,5 +124,3 @@ public:
     ANN_FLOP(k - i + 1) // increment floating ops
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/ArrayBoundedValidatorTest.h b/Framework/Kernel/test/ArrayBoundedValidatorTest.h
index c7c46fa0be3..da262d0a199 100644
--- a/Framework/Kernel/test/ArrayBoundedValidatorTest.h
+++ b/Framework/Kernel/test/ArrayBoundedValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ARRAYBOUNDEDVALIDATORTEST_H_
-#define ARRAYBOUNDEDVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/ArrayBoundedValidator.h"
 #include <array>
@@ -160,5 +159,3 @@ public:
     TS_ASSERT_EQUALS(vd.isValid(ad), "");
   }
 };
-
-#endif // ARRAYBOUNDEDVALIDATORTEST_H_
diff --git a/Framework/Kernel/test/ArrayLengthValidatorTest.h b/Framework/Kernel/test/ArrayLengthValidatorTest.h
index b99c3915a64..2ddba80cd76 100644
--- a/Framework/Kernel/test/ArrayLengthValidatorTest.h
+++ b/Framework/Kernel/test/ArrayLengthValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ARRAYLENGTHVALIDATORTEST_H_
-#define MANTID_KERNEL_ARRAYLENGTHVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -108,5 +107,3 @@ public:
     TS_ASSERT_DIFFERS(vi.isValid(a).length(), 0);
   }
 };
-
-#endif /* MANTID_KERNEL_ARRAYLENGTHVALIDATORTEST_H_ */
diff --git a/Framework/Kernel/test/ArrayOrderedPairsValidatorTest.h b/Framework/Kernel/test/ArrayOrderedPairsValidatorTest.h
index 57d8c0347ae..e4df9f516e7 100644
--- a/Framework/Kernel/test/ArrayOrderedPairsValidatorTest.h
+++ b/Framework/Kernel/test/ArrayOrderedPairsValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ARRAYBOUNDEDVALIDATORTEST_H_
-#define ARRAYBOUNDEDVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/ArrayOrderedPairsValidator.h"
 #include "MantidKernel/BoundedValidator.h"
@@ -51,5 +50,3 @@ public:
                      "Array has an odd number of entries (5).");
   }
 };
-
-#endif // ARRAYBOUNDEDVALIDATORTEST_H_
diff --git a/Framework/Kernel/test/ArrayPropertyTest.h b/Framework/Kernel/test/ArrayPropertyTest.h
index e4739ec1363..8b8d2dae900 100644
--- a/Framework/Kernel/test/ArrayPropertyTest.h
+++ b/Framework/Kernel/test/ArrayPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ARRAYPROPERTYTEST_H_
-#define ARRAYPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/ArrayProperty.h"
 #include <array>
@@ -426,5 +425,3 @@ private:
   ArrayProperty<double> *dProp;
   ArrayProperty<std::string> *sProp;
 };
-
-#endif /*ARRAYPROPERTYTEST_H_*/
diff --git a/Framework/Kernel/test/AtomTest.h b/Framework/Kernel/test/AtomTest.h
index 9ed7b9cfb45..1efbd65ead2 100644
--- a/Framework/Kernel/test/AtomTest.h
+++ b/Framework/Kernel/test/AtomTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ATOMTEST_H_
-#define ATOMTEST_H_
+#pragma once
 
 #include "MantidKernel/Atom.h"
 #include "MantidKernel/NeutronAtom.h"
@@ -106,5 +105,3 @@ private:
   std::vector<uint16_t> z_input;
   std::vector<std::string> symbol_input;
 };
-
-#endif // ATOMTEST_H_
diff --git a/Framework/Kernel/test/BinFinderTest.h b/Framework/Kernel/test/BinFinderTest.h
index 6aae5e23184..df22f0cdee9 100644
--- a/Framework/Kernel/test/BinFinderTest.h
+++ b/Framework/Kernel/test/BinFinderTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BINFINDERTEST_H_
-#define BINFINDERTEST_H_
+#pragma once
 
 #include "MantidKernel/BinFinder.h"
 #include "MantidKernel/System.h"
@@ -118,5 +117,3 @@ public:
     compareBin(1.0, -1, 16.1);
   }
 };
-
-#endif /*BINFINDERTEST_H_*/
diff --git a/Framework/Kernel/test/BinaryFileTest.h b/Framework/Kernel/test/BinaryFileTest.h
index fb7197bda1c..9b619e04102 100644
--- a/Framework/Kernel/test/BinaryFileTest.h
+++ b/Framework/Kernel/test/BinaryFileTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BINARYFILETEST_H_
-#define BINARYFILETEST_H_
+#pragma once
 
 #include "MantidKernel/BinaryFile.h"
 #include "MantidKernel/ConfigService.h"
@@ -191,5 +190,3 @@ public:
     TS_ASSERT_THROWS(file2.loadBlock(buffer, 10), const std::runtime_error &);
   }
 };
-
-#endif /*BINARYFILETEST_H_*/
diff --git a/Framework/Kernel/test/BinaryStreamReaderTest.h b/Framework/Kernel/test/BinaryStreamReaderTest.h
index 8ba84f27e3a..7e2333928e7 100644
--- a/Framework/Kernel/test/BinaryStreamReaderTest.h
+++ b/Framework/Kernel/test/BinaryStreamReaderTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_BINARYSTREAMREADERTEST_H_
-#define MANTID_KERNEL_BINARYSTREAMREADERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 #include <cxxtest/ValueTraits.h>
@@ -321,5 +320,3 @@ private:
 
   std::stringstream m_bytes;
 };
-
-#endif /* MANTID_KERNEL_BINARYSTREAMREADERTEST_H_ */
diff --git a/Framework/Kernel/test/BinaryStreamWriterTest.h b/Framework/Kernel/test/BinaryStreamWriterTest.h
index 7d1e7f746c3..a5e764a88a0 100644
--- a/Framework/Kernel/test/BinaryStreamWriterTest.h
+++ b/Framework/Kernel/test/BinaryStreamWriterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_BINARYSTREAMWRITERTEST_H_
-#define MANTID_KERNEL_BINARYSTREAMWRITERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 #include <cxxtest/ValueTraits.h>
@@ -129,5 +128,4 @@ private:
   }
 
   std::stringstream m_bytes;
-};
-#endif
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/Framework/Kernel/test/BoundedValidatorTest.h b/Framework/Kernel/test/BoundedValidatorTest.h
index 8076ba3cad2..bee69ede1e0 100644
--- a/Framework/Kernel/test/BoundedValidatorTest.h
+++ b/Framework/Kernel/test/BoundedValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BOUNDEDVALIDATORTEST_H_
-#define BOUNDEDVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/BoundedValidator.h"
 #include <cxxtest/TestSuite.h>
@@ -319,5 +318,3 @@ public:
     TS_ASSERT_EQUALS(ps.isValid("TA"), "");
   }
 };
-
-#endif /*BOUNDEDVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/CPUTimerTest.h b/Framework/Kernel/test/CPUTimerTest.h
index 2738ec51282..216db90037e 100644
--- a/Framework/Kernel/test/CPUTimerTest.h
+++ b/Framework/Kernel/test/CPUTimerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CPUTIMERTEST_H_
-#define MANTID_KERNEL_CPUTIMERTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -32,5 +31,3 @@ public:
     TS_ASSERT_THROWS_NOTHING(tim1.CPUfraction(false);)
   }
 };
-
-#endif /* MANTID_KERNEL_CPUTIMERTEST_H_ */
diff --git a/Framework/Kernel/test/CacheTest.h b/Framework/Kernel/test/CacheTest.h
index d69a03cc9bc..c6eb31374d0 100644
--- a/Framework/Kernel/test/CacheTest.h
+++ b/Framework/Kernel/test/CacheTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef CACHETEST_H_
-#define CACHETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -130,5 +129,3 @@ public:
   Cache<int, double> m_cacheGet;
   Cache<int, double> m_cacheSet;
 };
-
-#endif /*CACHETEST_H_*/
diff --git a/Framework/Kernel/test/CatalogInfoTest.h b/Framework/Kernel/test/CatalogInfoTest.h
index d3435ba8e14..720744101e8 100644
--- a/Framework/Kernel/test/CatalogInfoTest.h
+++ b/Framework/Kernel/test/CatalogInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_CATALOGINFOTEST_H_
-#define MANTID_CATALOGINFOTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -173,5 +172,3 @@ public:
     TS_ASSERT_EQUALS(original->soapEndPoint(), copy.soapEndPoint());
   }
 };
-
-#endif /*MANTID_CATALOGINFOTEST_H_*/
diff --git a/Framework/Kernel/test/ChebyshevPolyFitTest.h b/Framework/Kernel/test/ChebyshevPolyFitTest.h
index 7c614e73b6e..e6ef5cbfad7 100644
--- a/Framework/Kernel/test/ChebyshevPolyFitTest.h
+++ b/Framework/Kernel/test/ChebyshevPolyFitTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVPOLYFITTEST_H_
-#define MANTID_KERNEL_CHEBYSHEVPOLYFITTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -37,5 +36,3 @@ public:
     TS_ASSERT_DELTA(2, coeffs[2], delta);
   }
 };
-
-#endif /* MANTID_KERNEL_CHEBYSHEVPOLYFITTEST_H_ */
diff --git a/Framework/Kernel/test/ChebyshevPolynomialTest.h b/Framework/Kernel/test/ChebyshevPolynomialTest.h
index 0b4d87a926b..632b5066ce5 100644
--- a/Framework/Kernel/test/ChebyshevPolynomialTest.h
+++ b/Framework/Kernel/test/ChebyshevPolynomialTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVPOLYNOMIALTEST_H_
-#define MANTID_KERNEL_CHEBYSHEVPOLYNOMIALTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -38,5 +37,3 @@ public:
 
   // No test for out of range as there is an assert in there..
 };
-
-#endif /* MANTID_KERNEL_CHEBYSHEVPOLYNOMIALTEST_H_ */
diff --git a/Framework/Kernel/test/ChebyshevSeriesTest.h b/Framework/Kernel/test/ChebyshevSeriesTest.h
index c16999340ea..00380d3388f 100644
--- a/Framework/Kernel/test/ChebyshevSeriesTest.h
+++ b/Framework/Kernel/test/ChebyshevSeriesTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHEBYSHEVSERIESTEST_H_
-#define MANTID_KERNEL_CHEBYSHEVSERIESTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -36,5 +35,3 @@ public:
     TS_ASSERT_DELTA(0.821875, ChebyshevSeries(4)(coeffs, x), delta);
   }
 };
-
-#endif /* MANTID_KERNEL_CHEBYSHEVSERIESTEST_H_ */
diff --git a/Framework/Kernel/test/ChecksumHelperTest.h b/Framework/Kernel/test/ChecksumHelperTest.h
index 8fdd437ea71..2646b9d2aab 100644
--- a/Framework/Kernel/test/ChecksumHelperTest.h
+++ b/Framework/Kernel/test/ChecksumHelperTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_CHECKSUMHELPERTEST_H_
-#define MANTID_KERNEL_CHECKSUMHELPERTEST_H_
+#pragma once
 
 #include "MantidKernel/ChecksumHelper.h"
 #include "MantidKernel/System.h"
@@ -110,5 +109,3 @@ public:
     file.close();
   }
 };
-
-#endif /* MANTID_KERNEL_CHECKSUMHELPERTEST_H_ */
diff --git a/Framework/Kernel/test/CompositeValidatorTest.h b/Framework/Kernel/test/CompositeValidatorTest.h
index d176d078eb2..a1cc12aa904 100644
--- a/Framework/Kernel/test/CompositeValidatorTest.h
+++ b/Framework/Kernel/test/CompositeValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_COMPOSITEVALIDATORTEST_H_
-#define MANTID_KERNEL_COMPOSITEVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -111,5 +110,3 @@ public:
     TS_ASSERT_EQUALS(false, comp.contains<StringListValidator>());
   }
 };
-
-#endif /* MANTID_KERNEL_COMPOSITEVALIDATORTEST_H_ */
diff --git a/Framework/Kernel/test/ComputeResourceInfoTest.h b/Framework/Kernel/test/ComputeResourceInfoTest.h
index 607157e8ec6..c734fba9fe1 100644
--- a/Framework/Kernel/test/ComputeResourceInfoTest.h
+++ b/Framework/Kernel/test/ComputeResourceInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef COMPUTERESOURCEINFOTEST_H_
-#define COMPUTERESOURCEINFOTEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/FacilityInfo.h"
@@ -224,5 +223,3 @@ const std::string ComputeResourceInfoTest::testFacilityName = "ATestFacility";
 const std::string ComputeResourceInfoTest::fermiURL =
     "https://fermi.ornl.gov/MantidRemote";
 const std::string ComputeResourceInfoTest::fermiName = "Fermi";
-
-#endif // COMPUTERESOURCEINFOTEST_H_
diff --git a/Framework/Kernel/test/ConfigObserverTest.h b/Framework/Kernel/test/ConfigObserverTest.h
index a8dea35145b..33cd99cf272 100644
--- a/Framework/Kernel/test/ConfigObserverTest.h
+++ b/Framework/Kernel/test/ConfigObserverTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_CONFIGOBSERVERTEST_H_
-#define MANTID_CONFIGOBSERVERTEST_H_
+#pragma once
 
 #include "MantidKernel/ConfigObserver.h"
 #include "MantidKernel/ConfigService.h"
@@ -93,5 +92,4 @@ public:
 private:
   std::string m_searchDirectories;
   std::string m_defaultSaveDirectory;
-};
-#endif // MANTID_CONFIGSERVICEOBSERVERTEST_H_
+};
\ No newline at end of file
diff --git a/Framework/Kernel/test/ConfigPropertyObserverTest.h b/Framework/Kernel/test/ConfigPropertyObserverTest.h
index 3faa84cbc15..190c3cb85d0 100644
--- a/Framework/Kernel/test/ConfigPropertyObserverTest.h
+++ b/Framework/Kernel/test/ConfigPropertyObserverTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_CONFIGPROPERTYOBSERVERTEST_H_
-#define MANTID_CONFIGPROPERTYOBSERVERTEST_H_
+#pragma once
 
 #include "MantidKernel/ConfigPropertyObserver.h"
 #include "MantidKernel/ConfigService.h"
@@ -116,5 +115,4 @@ private:
   std::string m_searchDirectories;
   std::string m_defaultSaveDirectory;
   std::string m_retainedAlgorithms;
-};
-#endif // MANTID_CONFIGPROPERTYOBSERVERTEST_H_
+};
\ No newline at end of file
diff --git a/Framework/Kernel/test/ConfigServiceTest.h b/Framework/Kernel/test/ConfigServiceTest.h
index a4181d9037a..6b1221e2312 100644
--- a/Framework/Kernel/test/ConfigServiceTest.h
+++ b/Framework/Kernel/test/ConfigServiceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_CONFIGSERVICETEST_H_
-#define MANTID_CONFIGSERVICETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -738,5 +737,3 @@ private:
                        std::istreambuf_iterator<char>());
   }
 };
-
-#endif /*MANTID_CONFIGSERVICETEST_H_*/
diff --git a/Framework/Kernel/test/CowPtrTest.h b/Framework/Kernel/test/CowPtrTest.h
index d315c895d74..80c19f726bd 100644
--- a/Framework/Kernel/test/CowPtrTest.h
+++ b/Framework/Kernel/test/CowPtrTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef COW_PTR_TEST_H_
-#define COW_PTR_TEST_H_
+#pragma once
 
 #include "MantidKernel/cow_ptr.h"
 #include <boost/make_shared.hpp>
@@ -172,5 +171,3 @@ public:
     TS_ASSERT(cow == cow2);
   }
 };
-
-#endif /*COW_PTR_TEST_H_*/
diff --git a/Framework/Kernel/test/DataServiceTest.h b/Framework/Kernel/test/DataServiceTest.h
index 2e845c84bb2..3eaab610b57 100644
--- a/Framework/Kernel/test/DataServiceTest.h
+++ b/Framework/Kernel/test/DataServiceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATASERVICETEST_H_
-#define MANTID_KERNEL_DATASERVICETEST_H_
+#pragma once
 
 #include "MantidKernel/DataService.h"
 #include "MantidKernel/MultiThreaded.h"
@@ -527,5 +526,3 @@ public:
     TS_ASSERT(!FakeDataService::showingHiddenObjects());
   }
 };
-
-#endif /* MANTID_KERNEL_DATASERVICETEST_H_ */
diff --git a/Framework/Kernel/test/DateAndTimeHelpersTest.h b/Framework/Kernel/test/DateAndTimeHelpersTest.h
index 06b3ef8022c..c4aae36c6b2 100644
--- a/Framework/Kernel/test/DateAndTimeHelpersTest.h
+++ b/Framework/Kernel/test/DateAndTimeHelpersTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATEANDTIMEHELPERSTEST_H_
-#define MANTID_KERNEL_DATEANDTIMEHELPERSTEST_H_
+#pragma once
 
 #include "MantidKernel/DateAndTimeHelpers.h"
 #include "MantidTypes/Core/DateAndTime.h"
@@ -57,5 +56,3 @@ public:
                      createFromSanitizedISO8601("1979-09-19T00:00Z"));
   }
 };
-
-#endif /* MANTID_KERNEL_DATEANDTIMEHELPERSTEST_H_ */
diff --git a/Framework/Kernel/test/DateAndTimeTest.h b/Framework/Kernel/test/DateAndTimeTest.h
index d069bb62caa..64ab9c4bce6 100644
--- a/Framework/Kernel/test/DateAndTimeTest.h
+++ b/Framework/Kernel/test/DateAndTimeTest.h
@@ -11,8 +11,7 @@
  *      Author: janik
  */
 
-#ifndef DATEANDTIMETEST_H_
-#define DATEANDTIMETEST_H_
+#pragma once
 
 #include "MantidKernel/DateAndTime.h"
 #include "MantidKernel/System.h"
@@ -463,5 +462,3 @@ public:
     TS_ASSERT_EQUALS(times[3], DateAndTime("1990-01-02 03:04:02.000"));
   }
 };
-
-#endif /* DATEANDTIMETEST_H_ */
diff --git a/Framework/Kernel/test/DateTimeValidatorTest.h b/Framework/Kernel/test/DateTimeValidatorTest.h
index 591b32cfea2..46d99551d79 100644
--- a/Framework/Kernel/test/DateTimeValidatorTest.h
+++ b/Framework/Kernel/test/DateTimeValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DATETIMEVALIDATORTEST_H_
-#define MANTID_KERNEL_DATETIMEVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -77,5 +76,3 @@ public:
     TS_ASSERT_EQUALS(error, validator.isValid(input));
   }
 };
-
-#endif /* MANTID_KERNEL_DATETIMEVALIDATORTEST_H_ */
diff --git a/Framework/Kernel/test/DateValidatorTest.h b/Framework/Kernel/test/DateValidatorTest.h
index b7e0e57905e..d07e9009c4f 100644
--- a/Framework/Kernel/test/DateValidatorTest.h
+++ b/Framework/Kernel/test/DateValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef DATEVALIDATORTEST_H_
-#define DATEVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -47,5 +46,3 @@ public:
     TS_ASSERT_EQUALS(v.isValid("22/01/2006"), "")
   }
 };
-
-#endif /*DATEVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/DeltaEModeTest.h b/Framework/Kernel/test/DeltaEModeTest.h
index c6a2590d491..be1ad41cec8 100644
--- a/Framework/Kernel/test/DeltaEModeTest.h
+++ b/Framework/Kernel/test/DeltaEModeTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DELTAEMODETEST_H_
-#define MANTID_KERNEL_DELTAEMODETEST_H_
+#pragma once
 
 #include "MantidKernel/DeltaEMode.h"
 #include <cxxtest/TestSuite.h>
@@ -54,5 +53,3 @@ public:
 private:
   const std::string m_elasticString, m_directString, m_indirectString;
 };
-
-#endif /* MANTID_KERNEL_DELTAEMODETEST_H_ */
diff --git a/Framework/Kernel/test/DiffractionTest.h b/Framework/Kernel/test/DiffractionTest.h
index abc65a6f59b..a8d2c51db8e 100644
--- a/Framework/Kernel/test/DiffractionTest.h
+++ b/Framework/Kernel/test/DiffractionTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DIFFRACTIONTEST_H_
-#define MANTID_KERNEL_DIFFRACTIONTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 #include <limits>
@@ -78,5 +77,3 @@ public:
     TS_ASSERT_EQUALS(calcTofMax(DIFC, DIFA3, TZERO, TSUPERMAX), TZERO - 1.);
   }
 };
-
-#endif /* MANTID_KERNEL_DIFFRACTIONTEST_H_ */
diff --git a/Framework/Kernel/test/DirectoryValidatorTest.h b/Framework/Kernel/test/DirectoryValidatorTest.h
index 3d61d1e9868..6f009981b92 100644
--- a/Framework/Kernel/test/DirectoryValidatorTest.h
+++ b/Framework/Kernel/test/DirectoryValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef DIRECTORYVALIDATORTEST_H_
-#define DIRECTORYVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -48,5 +47,3 @@ public:
     dir.remove(); // clean up your folder
   }
 };
-
-#endif /*DIRECTORYVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/DiskBufferISaveableTest.h b/Framework/Kernel/test/DiskBufferISaveableTest.h
index 2cd67d4833e..9b9f3590fb4 100644
--- a/Framework/Kernel/test/DiskBufferISaveableTest.h
+++ b/Framework/Kernel/test/DiskBufferISaveableTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DISKBUFFER_ISAVEABLE_TEST_H_
-#define MANTID_KERNEL_DISKBUFFER_ISAVEABLE_TEST_H_
+#pragma once
 
 #include "MantidKernel/CPUTimer.h"
 #include "MantidKernel/DiskBuffer.h"
@@ -480,5 +479,3 @@ public:
               << " into MRU (no write buffer).\n";
   }
 };
-
-#endif /* MANTID_KERNEL_DISKBUFFERTEST_H_ */
diff --git a/Framework/Kernel/test/DiskBufferTest.h b/Framework/Kernel/test/DiskBufferTest.h
index 5bce2b1c0ac..7262b9c1022 100644
--- a/Framework/Kernel/test/DiskBufferTest.h
+++ b/Framework/Kernel/test/DiskBufferTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DISKBUFFERTEST_H_
-#define MANTID_KERNEL_DISKBUFFERTEST_H_
+#pragma once
 
 #include "MantidKernel/CPUTimer.h"
 #include "MantidKernel/DiskBuffer.h"
@@ -868,5 +867,3 @@ public:
               << " blocks in the free space list.\n";
   }
 };
-
-#endif /* MANTID_KERNEL_DISKBUFFERTEST_H_ */
diff --git a/Framework/Kernel/test/DllOpenTest.h b/Framework/Kernel/test/DllOpenTest.h
index 7c6303b2eed..8d71bf4f5b0 100644
--- a/Framework/Kernel/test/DllOpenTest.h
+++ b/Framework/Kernel/test/DllOpenTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_DLLOPENTEST_H
-#define MANTID_KERNEL_DLLOPENTEST_H
+#pragma once
 
 #include "MantidKernel/DllOpen.h"
 #include <cxxtest/TestSuite.h>
@@ -47,5 +46,3 @@ public:
 #endif
   }
 };
-
-#endif // MANTID_KERNEL_DLLOPENTEST_H
diff --git a/Framework/Kernel/test/DynamicFactoryTest.h b/Framework/Kernel/test/DynamicFactoryTest.h
index 84075a30d6d..c7f25b6cee5 100644
--- a/Framework/Kernel/test/DynamicFactoryTest.h
+++ b/Framework/Kernel/test/DynamicFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef DYNAMICFACTORYTEST_H_
-#define DYNAMICFACTORYTEST_H_
+#pragma once
 
 #include "MantidKernel/DynamicFactory.h"
 #include <cxxtest/TestSuite.h>
@@ -203,5 +202,3 @@ private:
       m_notificationObserver;
   bool m_updateNoticeReceived;
 };
-
-#endif /*DYNAMICFACTORYTEST_H_*/
diff --git a/Framework/Kernel/test/EigenConversionHelpersTest.h b/Framework/Kernel/test/EigenConversionHelpersTest.h
index 87d3d086de5..175a74ff573 100644
--- a/Framework/Kernel/test/EigenConversionHelpersTest.h
+++ b/Framework/Kernel/test/EigenConversionHelpersTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EIGENCONVERSIONHELPERSTEST_H_
-#define MANTID_KERNEL_EIGENCONVERSIONHELPERSTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -55,5 +54,3 @@ public:
     TS_ASSERT(toQuaterniond(toQuat(rot)).isApprox(rot, 1e-15));
   }
 };
-
-#endif /* MANTID_KERNEL_EIGENCONVERSIONHELPERSTEST_H_ */
diff --git a/Framework/Kernel/test/EnabledWhenPropertyTest.h b/Framework/Kernel/test/EnabledWhenPropertyTest.h
index a2430b9b549..b979fe8d0ff 100644
--- a/Framework/Kernel/test/EnabledWhenPropertyTest.h
+++ b/Framework/Kernel/test/EnabledWhenPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_ENABLEDWHENPROPERTYTEST_H_
-#define MANTID_KERNEL_ENABLEDWHENPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -226,5 +225,3 @@ private:
         std::move(condOne), std::move(condTwo), logicalOperator);
   }
 };
-
-#endif /* MANTID_KERNEL_ENABLEDWHENPROPERTYTEST_H_ */
diff --git a/Framework/Kernel/test/EnvironmentHistoryTest.h b/Framework/Kernel/test/EnvironmentHistoryTest.h
index c8111f5d72a..1f7a1b7efde 100644
--- a/Framework/Kernel/test/EnvironmentHistoryTest.h
+++ b/Framework/Kernel/test/EnvironmentHistoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef ENVIRONMENTHISTORYTEST_H_
-#define ENVIRONMENTHISTORYTEST_H_
+#pragma once
 
 #include "MantidKernel/ConfigService.h"
 #include "MantidKernel/EnvironmentHistory.h"
@@ -49,5 +48,3 @@ public:
     TS_ASSERT_EQUALS(output.str(), correctOutput);
   }
 };
-
-#endif /* ALGORITHMPARAMETERTEST_H_*/
diff --git a/Framework/Kernel/test/EqualBinsCheckerTest.h b/Framework/Kernel/test/EqualBinsCheckerTest.h
index 84bc84073c5..0f70e94e60c 100644
--- a/Framework/Kernel/test/EqualBinsCheckerTest.h
+++ b/Framework/Kernel/test/EqualBinsCheckerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_EQUALBINSCHECKERTEST_H_
-#define MANTID_KERNEL_EQUALBINSCHECKERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -101,5 +100,3 @@ private:
     return data;
   }
 };
-
-#endif /* MANTID_KERNEL_EQUALBINSCHECKERTEST_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/test/ErrorReporterTest.h b/Framework/Kernel/test/ErrorReporterTest.h
index a60777c115b..869a20e7702 100644
--- a/Framework/Kernel/test/ErrorReporterTest.h
+++ b/Framework/Kernel/test/ErrorReporterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_API_ERRORSERVICETEST_H_
-#define MANTID_API_ERRORSERVICETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -158,5 +157,3 @@ public:
     TS_ASSERT_EQUALS(root["stacktrace"].asString(), "");
   }
 };
-
-#endif /* MANTID_API_USAGESERVICETEST_H_ */
diff --git a/Framework/Kernel/test/FacilitiesTest.h b/Framework/Kernel/test/FacilitiesTest.h
index 815f823514d..95d46b0681c 100644
--- a/Framework/Kernel/test/FacilitiesTest.h
+++ b/Framework/Kernel/test/FacilitiesTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_FACILITIESTEST_H_
-#define MANTID_FACILITIESTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 #include <fstream>
@@ -222,5 +221,3 @@ private:
     return facility;
   }
 };
-
-#endif /*MANTID_FACILITIESTEST_H_*/
diff --git a/Framework/Kernel/test/FileDescriptorTest.h b/Framework/Kernel/test/FileDescriptorTest.h
index 962912e735f..4e2a44f8e18 100644
--- a/Framework/Kernel/test/FileDescriptorTest.h
+++ b/Framework/Kernel/test/FileDescriptorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FILEDESCRIPTORTEST_H_
-#define MANTID_KERNEL_FILEDESCRIPTORTEST_H_
+#pragma once
 
 #include <cstdio>
 #include <cxxtest/TestSuite.h>
@@ -175,5 +174,3 @@ private:
   std::string m_testNonNexusPath;
   std::string m_testAsciiPath;
 };
-
-#endif /* MANTID_KERNEL_FILEDESCRIPTORTEST_H_ */
diff --git a/Framework/Kernel/test/FileValidatorTest.h b/Framework/Kernel/test/FileValidatorTest.h
index 4bf90ac16ed..380c145a1d2 100644
--- a/Framework/Kernel/test/FileValidatorTest.h
+++ b/Framework/Kernel/test/FileValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef FILEVALIDATORTEST_H_
-#define FILEVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -105,5 +104,3 @@ public:
     TS_ASSERT_EQUALS(file_val.isValid(""), "File \"\" not found");
   }
 };
-
-#endif /*FILEVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/FilteredTimeSeriesPropertyTest.h b/Framework/Kernel/test/FilteredTimeSeriesPropertyTest.h
index 90f25824907..819e754ef21 100644
--- a/Framework/Kernel/test/FilteredTimeSeriesPropertyTest.h
+++ b/Framework/Kernel/test/FilteredTimeSeriesPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FILTEREDTIMESERIESPROPERTYTEST_H_
-#define MANTID_KERNEL_FILTEREDTIMESERIESPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/FilteredTimeSeriesProperty.h"
 #include <cxxtest/TestSuite.h>
@@ -117,5 +116,3 @@ private:
     return filter;
   }
 };
-
-#endif /* MANTID_KERNEL_FILTEREDTIMESERIESPROPERTYTEST_H_ */
diff --git a/Framework/Kernel/test/FloatingPointComparisonTest.h b/Framework/Kernel/test/FloatingPointComparisonTest.h
index 3e6304b56ea..41b9178dec4 100644
--- a/Framework/Kernel/test/FloatingPointComparisonTest.h
+++ b/Framework/Kernel/test/FloatingPointComparisonTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_FLOATINGPOINTCOMPARISONTEST_H_
-#define MANTID_KERNEL_FLOATINGPOINTCOMPARISONTEST_H_
+#pragma once
 
 #include "MantidKernel/FloatingPointComparison.h"
 #include <cfloat>
@@ -73,5 +72,3 @@ public:
     TS_ASSERT_EQUALS(Mantid::Kernel::gtEquals(-0.00002, -0.00001), false);
   }
 };
-
-#endif // MANTID_KERNEL_FLOATINGPOINTCOMPARISONTEST_H_
\ No newline at end of file
diff --git a/Framework/Kernel/test/FreeBlockTest.h b/Framework/Kernel/test/FreeBlockTest.h
index c8253259eb3..8d903fcbed5 100644
--- a/Framework/Kernel/test/FreeBlockTest.h
+++ b/Framework/Kernel/test/FreeBlockTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_API_FREEBLOCKTEST_H_
-#define MANTID_API_FREEBLOCKTEST_H_
+#pragma once
 
 #include "MantidKernel/FreeBlock.h"
 #include "MantidKernel/System.h"
@@ -76,5 +75,3 @@ public:
     TS_ASSERT_EQUALS(blocks[0].getSize(), 17);
   }
 };
-
-#endif /* MANTID_API_FREEBLOCKTEST_H_ */
diff --git a/Framework/Kernel/test/FunctionTaskTest.h b/Framework/Kernel/test/FunctionTaskTest.h
index ea0ceb4b6c9..2ce938fd42e 100644
--- a/Framework/Kernel/test/FunctionTaskTest.h
+++ b/Framework/Kernel/test/FunctionTaskTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef FUNCTIONTASKTEST_H_
-#define FUNCTIONTASKTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -55,5 +54,3 @@ public:
     TS_ASSERT_EQUALS(my_check_value, 68);
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/GlobTest.h b/Framework/Kernel/test/GlobTest.h
index 9bf3ea1ab8b..a30bd5bbb5e 100644
--- a/Framework/Kernel/test/GlobTest.h
+++ b/Framework/Kernel/test/GlobTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef GLOBTEST_H_
-#define GLOBTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -137,5 +136,3 @@ public:
     TS_ASSERT(!files.empty());
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/IPropertySettingsTest.h b/Framework/Kernel/test/IPropertySettingsTest.h
index 879d82957b4..95bfbd8f346 100644
--- a/Framework/Kernel/test/IPropertySettingsTest.h
+++ b/Framework/Kernel/test/IPropertySettingsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_IPROPERTYSETTINGSTEST_H_
-#define MANTID_KERNEL_IPROPERTYSETTINGSTEST_H_
+#pragma once
 
 #include "MantidKernel/IPropertySettings.h"
 #include "MantidKernel/System.h"
@@ -19,5 +18,3 @@ class IPropertySettingsTest : public CxxTest::TestSuite {
 public:
   void test_Something() {}
 };
-
-#endif /* MANTID_KERNEL_IPROPERTYSETTINGSTEST_H_ */
diff --git a/Framework/Kernel/test/ISaveableTest.h b/Framework/Kernel/test/ISaveableTest.h
index 21bfca6a0f9..37be4e4ac02 100644
--- a/Framework/Kernel/test/ISaveableTest.h
+++ b/Framework/Kernel/test/ISaveableTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_MDEVENTS_ISAVEABLETEST_H_
-#define MANTID_MDEVENTS_ISAVEABLETEST_H_
+#pragma once
 
 #include "MantidKernel/ISaveable.h"
 #include "MantidKernel/System.h"
@@ -20,5 +19,3 @@ public:
     // Bare interface, so nothing to test.
   }
 };
-
-#endif /* MANTID_MDEVENTS_ISAVEABLETEST_H_ */
diff --git a/Framework/Kernel/test/IValidatorTest.h b/Framework/Kernel/test/IValidatorTest.h
index f17b592a2e4..5e67e421d3d 100644
--- a/Framework/Kernel/test/IValidatorTest.h
+++ b/Framework/Kernel/test/IValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_IVALIDATORTEST_H_
-#define MANTID_KERNEL_IVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/IValidator.h"
 #include <boost/make_shared.hpp>
@@ -54,5 +53,3 @@ public:
     TS_ASSERT_EQUALS(noCopy.head(), testData.data());
   }
 };
-
-#endif /* MANTID_KERNEL_IVALIDATORTEST_H_ */
diff --git a/Framework/Kernel/test/IndexSetTest.h b/Framework/Kernel/test/IndexSetTest.h
index b81ef08e6a3..378475b5410 100644
--- a/Framework/Kernel/test/IndexSetTest.h
+++ b/Framework/Kernel/test/IndexSetTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INDEXSETTEST_H_
-#define MANTID_KERNEL_INDEXSETTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -84,5 +83,3 @@ public:
     TS_ASSERT_EQUALS(set[1], 2);
   }
 };
-
-#endif /* MANTID_KERNEL_INDEXSETTEST_H_ */
diff --git a/Framework/Kernel/test/InstrumentInfoTest.h b/Framework/Kernel/test/InstrumentInfoTest.h
index cd8042b7f3f..8f9efca7bf5 100644
--- a/Framework/Kernel/test/InstrumentInfoTest.h
+++ b/Framework/Kernel/test/InstrumentInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef INSTRUMENTINFOTEST_H_
-#define INSTRUMENTINFOTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -271,5 +270,4 @@ private:
 
     return new FacilityInfo(elem);
   }
-};
-#endif // INSTRUMENTINFOTEST_H_
+};
\ No newline at end of file
diff --git a/Framework/Kernel/test/InternetHelperTest.h b/Framework/Kernel/test/InternetHelperTest.h
index d7dec5654da..ecced68fcce 100644
--- a/Framework/Kernel/test/InternetHelperTest.h
+++ b/Framework/Kernel/test/InternetHelperTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INTERNETSERVICETEST_H_
-#define MANTID_KERNEL_INTERNETSERVICETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -243,5 +242,3 @@ public:
     TSM_ASSERT_EQUALS("Clear failed", internetHelper.headers().size(), 0);
   }
 };
-
-#endif /* MANTID_KERNEL_INTERNETSERVICETEST_H_ */
diff --git a/Framework/Kernel/test/InterpolationTest.h b/Framework/Kernel/test/InterpolationTest.h
index 490c358fab5..5dd3177bd59 100644
--- a/Framework/Kernel/test/InterpolationTest.h
+++ b/Framework/Kernel/test/InterpolationTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef INTERPOLATIONTEST_H_
-#define INTERPOLATIONTEST_H_
+#pragma once
 
 #include "MantidKernel/Interpolation.h"
 #include <ctime>
@@ -318,5 +317,3 @@ private:
     ~TestableInterpolation() override {}
   };
 };
-
-#endif /*INTERPOLATIONTEST_H_*/
diff --git a/Framework/Kernel/test/InvisiblePropertyTest.h b/Framework/Kernel/test/InvisiblePropertyTest.h
index c06bb2159c2..367beceb8c3 100644
--- a/Framework/Kernel/test/InvisiblePropertyTest.h
+++ b/Framework/Kernel/test/InvisiblePropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_INVISIBLEPROPERTYTEST_H_
-#define MANTID_KERNEL_INVISIBLEPROPERTYTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -41,5 +40,3 @@ public:
 private:
   const PropertyManagerOwner m_owner;
 };
-
-#endif /* MANTID_KERNEL_INVISIBLEPROPERTYTEST_H_ */
diff --git a/Framework/Kernel/test/ListValidatorTest.h b/Framework/Kernel/test/ListValidatorTest.h
index 133bbe68ab3..c204601ec9e 100644
--- a/Framework/Kernel/test/ListValidatorTest.h
+++ b/Framework/Kernel/test/ListValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef LISTVALIDATORTEST_H_
-#define LISTVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -144,5 +143,3 @@ public:
     TS_ASSERT_EQUALS(validator.isValid("1"), "_alias")
   }
 };
-
-#endif /*LISTVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/LiveListenerInfoTest.h b/Framework/Kernel/test/LiveListenerInfoTest.h
index 52d696038a2..16ad23da52f 100644
--- a/Framework/Kernel/test/LiveListenerInfoTest.h
+++ b/Framework/Kernel/test/LiveListenerInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef LIVELISTENERINFOTEST_H_
-#define LIVELISTENERINFOTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -181,5 +180,3 @@ private:
     return std::make_unique<FacilityInfo>(elem);
   }
 };
-
-#endif // LIVELISTENERINFOTEST_H_
diff --git a/Framework/Kernel/test/LogFilterTest.h b/Framework/Kernel/test/LogFilterTest.h
index c397d8b0231..5cbcfa8615b 100644
--- a/Framework/Kernel/test/LogFilterTest.h
+++ b/Framework/Kernel/test/LogFilterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef LOGFILTERTEST_H_
-#define LOGFILTERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -381,5 +380,3 @@ private:
     return std::mktime(&time_since_1900);
   }
 };
-
-#endif /*LOGFILTERTEST_H_*/
diff --git a/Framework/Kernel/test/LogParserTest.h b/Framework/Kernel/test/LogParserTest.h
index b240efee724..56f6a367920 100644
--- a/Framework/Kernel/test/LogParserTest.h
+++ b/Framework/Kernel/test/LogParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef LOGPARSERTEST_H_
-#define LOGPARSERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -855,5 +854,3 @@ private:
   TmpFile log_num_repeat;        // num log with repeating lines
   TmpFile log_str_continuations; // string log with continuation lines
 };
-
-#endif /*LOGPARSERTEST_H_*/
diff --git a/Framework/Kernel/test/LoggerTest.h b/Framework/Kernel/test/LoggerTest.h
index e6babd11b53..107b6aac07f 100644
--- a/Framework/Kernel/test/LoggerTest.h
+++ b/Framework/Kernel/test/LoggerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_LOGGERTEST_H_
-#define MANTID_KERNEL_LOGGERTEST_H_
+#pragma once
 
 #include "MantidKernel/FunctionTask.h"
 #include "MantidKernel/Logger.h"
@@ -150,5 +149,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_KERNEL_LOGGERTEST_H_ */
diff --git a/Framework/Kernel/test/MDAxisValidatorTest.h b/Framework/Kernel/test/MDAxisValidatorTest.h
index e2f9ae2905c..60b459c0c7e 100644
--- a/Framework/Kernel/test/MDAxisValidatorTest.h
+++ b/Framework/Kernel/test/MDAxisValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDAXISVALIDATORTEST_H_
-#define MANTID_KERNEL_MDAXISVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -102,5 +101,3 @@ private:
     return checker;
   }
 };
-
-#endif /* MANTID_KERNEL_MDAXISVALIDATORTEST_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/test/MDUnitFactoryTest.h b/Framework/Kernel/test/MDUnitFactoryTest.h
index e10a72ed8cc..a7a6d7c48c4 100644
--- a/Framework/Kernel/test/MDUnitFactoryTest.h
+++ b/Framework/Kernel/test/MDUnitFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDUNITFACTORYTEST_H_
-#define MANTID_KERNEL_MDUNITFACTORYTEST_H_
+#pragma once
 
 #include "MantidKernel/MDUnit.h"
 #include "MantidKernel/MDUnitFactory.h"
@@ -140,5 +139,3 @@ public:
     TS_ASSERT(dynamic_cast<LabelUnit *>(chain->create("Anything else").get()));
   }
 };
-
-#endif /* MANTID_KERNEL_MDUNITFACTORYTEST_H_ */
diff --git a/Framework/Kernel/test/MDUnitTest.h b/Framework/Kernel/test/MDUnitTest.h
index b01759807f9..5e5fc463b1f 100644
--- a/Framework/Kernel/test/MDUnitTest.h
+++ b/Framework/Kernel/test/MDUnitTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MDUNITTEST_H_
-#define MANTID_KERNEL_MDUNITTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -104,5 +103,3 @@ public:
     delete b;
   }
 };
-
-#endif /* MANTID_KERNEL_MDUNITTEST_H_ */
diff --git a/Framework/Kernel/test/MRUListTest.h b/Framework/Kernel/test/MRUListTest.h
index 2b475e71039..bc90d5e3039 100644
--- a/Framework/Kernel/test/MRUListTest.h
+++ b/Framework/Kernel/test/MRUListTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MRULISTTEST_H_
-#define MRULISTTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -95,5 +94,3 @@ public:
     TS_ASSERT_EQUALS(m.size(), 100);
   }
 };
-
-#endif /* MRULISTTEST_H_ */
diff --git a/Framework/Kernel/test/MagneticIonTest.h b/Framework/Kernel/test/MagneticIonTest.h
index 6ef6f9a45ca..b5c4bcc73cd 100644
--- a/Framework/Kernel/test/MagneticIonTest.h
+++ b/Framework/Kernel/test/MagneticIonTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MAGNETICIONTEST_H_
-#define MAGNETICIONTEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/MagneticIon.h"
@@ -84,5 +83,3 @@ private:
     }
   }
 };
-
-#endif // MAGNETICIONTEST_H_
diff --git a/Framework/Kernel/test/MakeCowTest.h b/Framework/Kernel/test/MakeCowTest.h
index daf5a082a1e..d398bf72b7f 100644
--- a/Framework/Kernel/test/MakeCowTest.h
+++ b/Framework/Kernel/test/MakeCowTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MAKE_COW_TEST_H_
-#define MAKE_COW_TEST_H_
+#pragma once
 
 #include "MantidKernel/make_cow.h"
 #include <cxxtest/TestSuite.h>
@@ -44,5 +43,3 @@ public:
                       product->args, 2);
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/MandatoryValidatorTest.h b/Framework/Kernel/test/MandatoryValidatorTest.h
index 1b19d4472d0..eb545739625 100644
--- a/Framework/Kernel/test/MandatoryValidatorTest.h
+++ b/Framework/Kernel/test/MandatoryValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANDATORYVALIDATORTEST_H_
-#define MANDATORYVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/MandatoryValidator.h"
 #include "MantidKernel/OptionalBool.h"
@@ -107,5 +106,3 @@ public:
     TS_ASSERT(validator.isValid(notDefaultIsFalse).empty());
   }
 };
-
-#endif /*MANDATORYVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/MaskedPropertyTest.h b/Framework/Kernel/test/MaskedPropertyTest.h
index b4f6c6e4e27..9a81baed282 100644
--- a/Framework/Kernel/test/MaskedPropertyTest.h
+++ b/Framework/Kernel/test/MaskedPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MASKEDPROPERTYTEST_H_
-#define MASKEDPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/MaskedProperty.h"
 #include "MantidKernel/PropertyHistory.h"
@@ -31,5 +30,3 @@ public:
     TS_ASSERT(!prohist.value().compare(""));
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/MaterialBuilderTest.h b/Framework/Kernel/test/MaterialBuilderTest.h
index 97d577ed9fd..5e44fb53941 100644
--- a/Framework/Kernel/test/MaterialBuilderTest.h
+++ b/Framework/Kernel/test/MaterialBuilderTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATERIALBUILDERTEST_H_
-#define MANTID_KERNEL_MATERIALBUILDERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -250,5 +249,3 @@ public:
     TS_ASSERT_THROWS(builder.build(), const std::runtime_error &)
   }
 };
-
-#endif /* MANTID_KERNEL_MATERIALBUILDERTEST_H_ */
diff --git a/Framework/Kernel/test/MaterialTest.h b/Framework/Kernel/test/MaterialTest.h
index 778243f12f3..77321a0c721 100644
--- a/Framework/Kernel/test/MaterialTest.h
+++ b/Framework/Kernel/test/MaterialTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_TESTMATERIAL__
-#define MANTID_TESTMATERIAL__
+#pragma once
 
 #include <cmath>
 #include <cxxtest/TestSuite.h>
@@ -259,5 +258,4 @@ public:
     TS_ASSERT_EQUALS(cf[3].atom->symbol, "O");
     TS_ASSERT_DELTA(cf[3].multiplicity, 6.56, .01);
   }
-};
-#endif
+};
\ No newline at end of file
diff --git a/Framework/Kernel/test/MaterialXMLParserTest.h b/Framework/Kernel/test/MaterialXMLParserTest.h
index 8ee5c314adb..98ac2f3dee8 100644
--- a/Framework/Kernel/test/MaterialXMLParserTest.h
+++ b/Framework/Kernel/test/MaterialXMLParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MATERIALXMLPARSERTEST_H_
-#define MANTID_KERNEL_MATERIALXMLPARSERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -170,5 +169,3 @@ private:
     return parser.parse(&src);
   }
 };
-
-#endif /* MANTID_KERNEL_MATERIALXMLPARSERTEST_H_ */
diff --git a/Framework/Kernel/test/MatrixPropertyTest.h b/Framework/Kernel/test/MatrixPropertyTest.h
index 2c2c67fa696..162399e893d 100644
--- a/Framework/Kernel/test/MatrixPropertyTest.h
+++ b/Framework/Kernel/test/MatrixPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MATRIXPROPERTYTEST_H_
-#define MATRIXPROPERTYTEST_H_
+#pragma once
 //-----------------------------------------------------------------------------
 // Includes
 //-----------------------------------------------------------------------------
@@ -104,5 +103,3 @@ public:
     }
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/MatrixTest.h b/Framework/Kernel/test/MatrixTest.h
index dea93d9e0c1..66e48677d52 100644
--- a/Framework/Kernel/test/MatrixTest.h
+++ b/Framework/Kernel/test/MatrixTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_TESTMATIX__
-#define MANTID_TESTMATIX__
+#pragma once
 
 #include <algorithm>
 #include <cmath>
@@ -878,5 +877,3 @@ private:
     }
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/MemoryTest.h b/Framework/Kernel/test/MemoryTest.h
index 43620f0f56c..fa23112c81b 100644
--- a/Framework/Kernel/test/MemoryTest.h
+++ b/Framework/Kernel/test/MemoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MEMORYTEST_H_
-#define MANTID_KERNEL_MEMORYTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -62,5 +61,3 @@ public:
     pool.joinAll();
   }
 };
-
-#endif /* MANTID_KERNEL_MEMORYTEST_H_ */
diff --git a/Framework/Kernel/test/MersenneTwisterTest.h b/Framework/Kernel/test/MersenneTwisterTest.h
index 2166fd0791b..4f2b4d4809a 100644
--- a/Framework/Kernel/test/MersenneTwisterTest.h
+++ b/Framework/Kernel/test/MersenneTwisterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MERSENNETWISTERTEST_H_
-#define MERSENNETWISTERTEST_H_
+#pragma once
 
 #include "MantidKernel/MersenneTwister.h"
 #include <cxxtest/TestSuite.h>
@@ -167,5 +166,3 @@ private:
     return values;
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/MultiFileNameParserTest.h b/Framework/Kernel/test/MultiFileNameParserTest.h
index 55248fa627b..7d8b5a358e8 100644
--- a/Framework/Kernel/test/MultiFileNameParserTest.h
+++ b/Framework/Kernel/test/MultiFileNameParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_MULTIFILENAMEPARSERTEST_H_
-#define MANTID_KERNEL_MULTIFILENAMEPARSERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -493,5 +492,3 @@ public:
     TS_ASSERT_EQUALS(filenames[1][2], "TST00000000301");
   }
 };
-
-#endif /* MANTID_KERNEL_MULTIFILENAMEPARSERTEST_H_ */
diff --git a/Framework/Kernel/test/MultiFileValidatorTest.h b/Framework/Kernel/test/MultiFileValidatorTest.h
index 74f536bc044..1944932bff8 100644
--- a/Framework/Kernel/test/MultiFileValidatorTest.h
+++ b/Framework/Kernel/test/MultiFileValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MULTIFILEVALIDATORTEST_H_
-#define MULTIFILEVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -146,5 +145,3 @@ public:
     TS_ASSERT(file_val.isValid(file).empty());
   }
 };
-
-#endif /*MULTIFILEVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/MutexTest.h b/Framework/Kernel/test/MutexTest.h
index fe515e02dff..66dae7abd6b 100644
--- a/Framework/Kernel/test/MutexTest.h
+++ b/Framework/Kernel/test/MutexTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MUTEXTEST_H
-#define MUTEXTEST_H
+#pragma once
 
 #include "MantidKernel/CPUTimer.h"
 #include "MantidKernel/FunctionTask.h"
@@ -97,5 +96,3 @@ public:
                       DATA_SIZE + numTasks / 10)
   }
 };
-
-#endif /* MUTEXTEST_H */
diff --git a/Framework/Kernel/test/NDPseudoRandomNumberGeneratorTest.h b/Framework/Kernel/test/NDPseudoRandomNumberGeneratorTest.h
index c40e861108a..b8efc2fb95e 100644
--- a/Framework/Kernel/test/NDPseudoRandomNumberGeneratorTest.h
+++ b/Framework/Kernel/test/NDPseudoRandomNumberGeneratorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef NDPSEUDORANDOMNUMBERGENERATORTEST_H_
-#define NDPSEUDORANDOMNUMBERGENERATORTEST_H_
+#pragma once
 
 #include "MantidKernel/MersenneTwister.h"
 #include "MantidKernel/NDPseudoRandomNumberGenerator.h"
@@ -88,5 +87,3 @@ private:
     return values;
   }
 };
-
-#endif // NDPSEUDORANDOMNUMBERGENERATORTEST_H_
diff --git a/Framework/Kernel/test/NDRandomNumberGeneratorTest.h b/Framework/Kernel/test/NDRandomNumberGeneratorTest.h
index c057725ef90..92734434788 100644
--- a/Framework/Kernel/test/NDRandomNumberGeneratorTest.h
+++ b/Framework/Kernel/test/NDRandomNumberGeneratorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef NDRandomNumberGeneratorTEST_H_
-#define NDRandomNumberGeneratorTEST_H_
+#pragma once
 
 #include "MantidKernel/NDRandomNumberGenerator.h"
 #include "MantidKernel/WarningSuppressions.h"
@@ -50,5 +49,3 @@ public:
     TS_ASSERT_EQUALS(randGen.nextPoint().size(), randGen.numberOfDimensions());
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/NearestNeighboursTest.h b/Framework/Kernel/test/NearestNeighboursTest.h
index 3fbfd47a399..39e454277ee 100644
--- a/Framework/Kernel/test/NearestNeighboursTest.h
+++ b/Framework/Kernel/test/NearestNeighboursTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NEARESTNEIGHBOURSTEST_H_
-#define MANTID_KERNEL_NEARESTNEIGHBOURSTEST_H_
+#pragma once
 
 #include "MantidKernel/NearestNeighbours.h"
 #include <cxxtest/TestSuite.h>
@@ -73,5 +72,3 @@ public:
     TS_ASSERT_DELTA(dist, 2.21, 0.01)
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/NeutronAtomTest.h b/Framework/Kernel/test/NeutronAtomTest.h
index d34e264bdd9..d371aed6a02 100644
--- a/Framework/Kernel/test/NeutronAtomTest.h
+++ b/Framework/Kernel/test/NeutronAtomTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef NEUTRONATOMTEST_H_
-#define NEUTRONATOMTEST_H_
+#pragma once
 
 #include "MantidKernel/NeutronAtom.h"
 #include <cxxtest/TestSuite.h>
@@ -62,5 +61,3 @@ public:
     TS_ASSERT_THROWS(getNeutronAtom(97), const std::runtime_error &);
   }
 };
-
-#endif // NEUTRONATOMTEST_H_
diff --git a/Framework/Kernel/test/NexusDescriptorTest.h b/Framework/Kernel/test/NexusDescriptorTest.h
index 4715f36e604..8ceb4423a2a 100644
--- a/Framework/Kernel/test/NexusDescriptorTest.h
+++ b/Framework/Kernel/test/NexusDescriptorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_NEXUSDESCRIPTORTEST_H_
-#define MANTID_KERNEL_NEXUSDESCRIPTORTEST_H_
+#pragma once
 
 #include "MantidKernel/ConfigService.h"
 #include "MantidKernel/NexusDescriptor.h"
@@ -179,5 +178,3 @@ private:
   std::string m_testNonHDFPath;
   boost::shared_ptr<NexusDescriptor> m_testHDF5;
 };
-
-#endif /* MANTID_KERNEL_NEXUSDESCRIPTORTEST_H_ */
diff --git a/Framework/Kernel/test/NullValidatorTest.h b/Framework/Kernel/test/NullValidatorTest.h
index e61c42e5e18..7b4fa7cb48d 100644
--- a/Framework/Kernel/test/NullValidatorTest.h
+++ b/Framework/Kernel/test/NullValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef NULLVALIDATORTEST_H_
-#define NULLVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/NullValidator.h"
 #include <boost/make_shared.hpp>
@@ -49,5 +48,3 @@ public:
     TS_ASSERT_EQUALS(p.isValid("ta"), "");
   }
 };
-
-#endif /*NULLVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/OptionalBoolTest.h b/Framework/Kernel/test/OptionalBoolTest.h
index ec3cfbe417b..6f7ce677f47 100644
--- a/Framework/Kernel/test/OptionalBoolTest.h
+++ b/Framework/Kernel/test/OptionalBoolTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_OPTIONALBOOLTEST_H_
-#define MANTID_KERNEL_OPTIONALBOOLTEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/OptionalBool.h"
@@ -137,5 +136,3 @@ public:
     TS_ASSERT_THROWS(encodeAsJson(truth), const NotImplementedError &);
   }
 };
-
-#endif /* MANTID_KERNEL_OPTIONALBOOLTEST_H_ */
diff --git a/Framework/Kernel/test/PrecompiledHeader.h b/Framework/Kernel/test/PrecompiledHeader.h
index 7f5e823c069..bb085a956df 100644
--- a/Framework/Kernel/test/PrecompiledHeader.h
+++ b/Framework/Kernel/test/PrecompiledHeader.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNELTEST_PRECOMPILEDHEADER_H_
-#define MANTID_KERNELTEST_PRECOMPILEDHEADER_H_
+#pragma once
 
 // cxxtest
 #include <cxxtest/WrappedTestSuite.h>
@@ -17,5 +16,3 @@
 #include <set>
 #include <string>
 #include <vector>
-
-#endif // MANTID_KERNEL_PRECOMPILEDHEADER_H_
\ No newline at end of file
diff --git a/Framework/Kernel/test/ProgressBaseTest.h b/Framework/Kernel/test/ProgressBaseTest.h
index 68db552e3d0..43135f1c235 100644
--- a/Framework/Kernel/test/ProgressBaseTest.h
+++ b/Framework/Kernel/test/ProgressBaseTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROGRESSBASETEST_H_
-#define MANTID_KERNEL_PROGRESSBASETEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -148,5 +147,3 @@ public:
     TS_ASSERT_DELTA(p.last_report_value, 1e-2, 1e-6);
   }
 };
-
-#endif /* MANTID_KERNEL_PROGRESSBASETEST_H_ */
diff --git a/Framework/Kernel/test/PropertyHistoryTest.h b/Framework/Kernel/test/PropertyHistoryTest.h
index 76d0cd7d5db..a741b0322aa 100644
--- a/Framework/Kernel/test/PropertyHistoryTest.h
+++ b/Framework/Kernel/test/PropertyHistoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYHISTORYTEST_H_
-#define PROPERTYHISTORYTEST_H_
+#pragma once
 
 #include "MantidKernel/EmptyValues.h"
 #include "MantidKernel/Property.h"
@@ -112,5 +111,3 @@ public:
     TS_ASSERT_EQUALS(prop.isEmptyDefault(), false);
   }
 };
-
-#endif /* PROPERTYHISTORYTEST_H_*/
diff --git a/Framework/Kernel/test/PropertyManagerDataServiceTest.h b/Framework/Kernel/test/PropertyManagerDataServiceTest.h
index 47becf55976..1fb0ae1bc3d 100644
--- a/Framework/Kernel/test/PropertyManagerDataServiceTest.h
+++ b/Framework/Kernel/test/PropertyManagerDataServiceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYMANAGERDATASERVICETEST_H_
-#define PROPERTYMANAGERDATASERVICETEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/PropertyManager.h"
@@ -112,5 +111,3 @@ public:
 private:
   boost::shared_ptr<PropertyManager> inst1, inst2;
 };
-
-#endif /*PROPERTYMANAGERDATASERVICETEST_H_*/
diff --git a/Framework/Kernel/test/PropertyManagerPropertyTest.h b/Framework/Kernel/test/PropertyManagerPropertyTest.h
index 676aa205bb7..4e3393199cb 100644
--- a/Framework/Kernel/test/PropertyManagerPropertyTest.h
+++ b/Framework/Kernel/test/PropertyManagerPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_PROPERTYMANAGERPROPERTYTEST_H_
-#define MANTID_KERNEL_PROPERTYMANAGERPROPERTYTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -266,5 +265,3 @@ private:
     return testMgr;
   }
 };
-
-#endif /* MANTID_KERNEL_PROPERTYMANAGERPROPERTYTEST_H_ */
diff --git a/Framework/Kernel/test/PropertyManagerTest.h b/Framework/Kernel/test/PropertyManagerTest.h
index dd048c22d4f..9c6f4d9085b 100644
--- a/Framework/Kernel/test/PropertyManagerTest.h
+++ b/Framework/Kernel/test/PropertyManagerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYMANAGERTEST_H_
-#define PROPERTYMANAGERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -697,5 +696,3 @@ private:
   /// Test filter
   boost::scoped_ptr<TimeSeriesProperty<bool>> m_filter;
 };
-
-#endif /*PROPERTYMANAGERTEST_H_*/
diff --git a/Framework/Kernel/test/PropertyNexusTest.h b/Framework/Kernel/test/PropertyNexusTest.h
index 21d9adef6af..0a363b61073 100644
--- a/Framework/Kernel/test/PropertyNexusTest.h
+++ b/Framework/Kernel/test/PropertyNexusTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_API_PROPERTYNEXUSTEST_H_
-#define MANTID_API_PROPERTYNEXUSTEST_H_
+#pragma once
 
 #include "MantidKernel/DateAndTime.h"
 #include "MantidKernel/PropertyNexus.h"
@@ -106,5 +105,3 @@ public:
         &tsps);
   }
 };
-
-#endif /* MANTID_API_PROPERTYNEXUSTEST_H_ */
diff --git a/Framework/Kernel/test/PropertyTest.h b/Framework/Kernel/test/PropertyTest.h
index bfc19738634..68bde5ea873 100644
--- a/Framework/Kernel/test/PropertyTest.h
+++ b/Framework/Kernel/test/PropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYTEST_H_
-#define PROPERTYTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -121,5 +120,3 @@ public:
 private:
   std::unique_ptr<Property> p;
 };
-
-#endif /*PROPERTYTEST_H_*/
diff --git a/Framework/Kernel/test/PropertyWithValueJSONTest.h b/Framework/Kernel/test/PropertyWithValueJSONTest.h
index bd783446e9a..d25b48b73ba 100644
--- a/Framework/Kernel/test/PropertyWithValueJSONTest.h
+++ b/Framework/Kernel/test/PropertyWithValueJSONTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYWITHVALUEJSONDECODERTEST_H
-#define PROPERTYWITHVALUEJSONDECODERTEST_H
+#pragma once
 
 #include "MantidKernel/ArrayProperty.h"
 #include "MantidKernel/PropertyManager.h"
@@ -209,5 +208,3 @@ private:
     return jsonVal;
   }
 };
-
-#endif // PROPERTYWITHVALUEJSONDECODERTEST_H
diff --git a/Framework/Kernel/test/PropertyWithValueTest.h b/Framework/Kernel/test/PropertyWithValueTest.h
index 17c463b17c0..67b49235b84 100644
--- a/Framework/Kernel/test/PropertyWithValueTest.h
+++ b/Framework/Kernel/test/PropertyWithValueTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef PROPERTYWITHVALUETEST_H_
-#define PROPERTYWITHVALUETEST_H_
+#pragma once
 
 #include "MantidKernel/BoundedValidator.h"
 #include "MantidKernel/DataItem.h"
@@ -776,5 +775,3 @@ private:
   PropertyWithValue<int64_t> *lProp;
   PropertyWithValue<OptionalBool> *bProp;
 };
-
-#endif /*PROPERTYWITHVALUETEST_H_*/
diff --git a/Framework/Kernel/test/ProxyInfoTest.h b/Framework/Kernel/test/ProxyInfoTest.h
index 0b55728b9ba..54a7fef66a2 100644
--- a/Framework/Kernel/test/ProxyInfoTest.h
+++ b/Framework/Kernel/test/ProxyInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_SCRIPTREPOSITORY_PROXYINFOTEST_H_
-#define MANTID_SCRIPTREPOSITORY_PROXYINFOTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -99,5 +98,3 @@ public:
     TS_ASSERT(b.emptyProxy())
   }
 };
-
-#endif /* MANTID_SCRIPTREPOSITORY_PROXYINFOTEST_H_ */
diff --git a/Framework/Kernel/test/QuatTest.h b/Framework/Kernel/test/QuatTest.h
index ea9bae83a6a..68e52260887 100644
--- a/Framework/Kernel/test/QuatTest.h
+++ b/Framework/Kernel/test/QuatTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_TESTQUAT__
-#define MANTID_TESTQUAT__
+#pragma once
 
 #include "MantidKernel/Matrix.h"
 #include "MantidKernel/Quat.h"
@@ -591,5 +590,3 @@ public:
     TS_ASSERT_EQUALS(b, Quat(4, 5, 6, 7));
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/ReadLockTest.h b/Framework/Kernel/test/ReadLockTest.h
index 24401a87d6d..f5a091a3404 100644
--- a/Framework/Kernel/test/ReadLockTest.h
+++ b/Framework/Kernel/test/ReadLockTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_READLOCKTEST_H_
-#define MANTID_KERNEL_READLOCKTEST_H_
+#pragma once
 
 #include "MantidKernel/ReadLock.h"
 
@@ -44,5 +43,3 @@ public:
     // ReadLock * lock = new ReadLock(item);
   }
 };
-
-#endif /* MANTID_KERNEL_READLOCKTEST_H_ */
diff --git a/Framework/Kernel/test/RebinHistogramTest.h b/Framework/Kernel/test/RebinHistogramTest.h
index 3f668d9bbca..beb87878872 100644
--- a/Framework/Kernel/test/RebinHistogramTest.h
+++ b/Framework/Kernel/test/RebinHistogramTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef REBINHISTOGRAM_TEST_H_
-#define REBINHISTOGRAM_TEST_H_
+#pragma once
 
 #include "MantidKernel/VectorHelper.h"
 #include <algorithm>
@@ -127,5 +126,3 @@ private:
       largerBinEdges[i] = binEdges[(2 * i)];
   }
 };
-
-#endif // REBINHISTOGRAM_TEST_H_/
diff --git a/Framework/Kernel/test/RebinParamsValidatorTest.h b/Framework/Kernel/test/RebinParamsValidatorTest.h
index 3cc0d64b4e0..266e7ee7667 100644
--- a/Framework/Kernel/test/RebinParamsValidatorTest.h
+++ b/Framework/Kernel/test/RebinParamsValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef REBINPARAMSVALIDATORTEST_H_
-#define REBINPARAMSVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/RebinParamsValidator.h"
 #include <boost/make_shared.hpp>
@@ -105,5 +104,3 @@ public:
 private:
   RebinParamsValidator standardValidator;
 };
-
-#endif /*REBINPARAMSVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/RegexStringsTest.h b/Framework/Kernel/test/RegexStringsTest.h
index c00e0531e0b..1257e653ba3 100644
--- a/Framework/Kernel/test/RegexStringsTest.h
+++ b/Framework/Kernel/test/RegexStringsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_TESTREGEXSUPPORT__
-#define MANTID_TESTREGEXSUPPORT__
+#pragma once
 
 #include <algorithm>
 #include <cmath>
@@ -174,5 +173,3 @@ public:
     TS_ASSERT_EQUALS(output, "2007-11-16T13:32:38 BEGIN");
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/SLSQPMinimizerTest.h b/Framework/Kernel/test/SLSQPMinimizerTest.h
index 1a6fc47ba6f..93c3ade9b16 100644
--- a/Framework/Kernel/test/SLSQPMinimizerTest.h
+++ b/Framework/Kernel/test/SLSQPMinimizerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SLSQPMINIMIZERTEST_H_
-#define MANTID_KERNEL_SLSQPMINIMIZERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -197,5 +196,3 @@ private:
 
   const size_t m_nparams;
 };
-
-#endif /* MANTID_KERNEL_SLSQPMINIMIZERTEST_H_ */
diff --git a/Framework/Kernel/test/ShrinkToFitTest.h b/Framework/Kernel/test/ShrinkToFitTest.h
index 7264019b7ce..91d486f7533 100644
--- a/Framework/Kernel/test/ShrinkToFitTest.h
+++ b/Framework/Kernel/test/ShrinkToFitTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_SHRINKTOFITTEST_H_
-#define MANTID_SHRINKTOFITTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 #include <string>
@@ -53,5 +52,3 @@ public:
     TS_ASSERT_LESS_THAN_EQUALS(capacityAfterShrinkToFit, original.capacity());
   }
 };
-
-#endif // MANTID_SHRINKTOFITTEST_H_
diff --git a/Framework/Kernel/test/SimpleJSONTest.h b/Framework/Kernel/test/SimpleJSONTest.h
index 9140e5a40b9..0345fadd8b7 100644
--- a/Framework/Kernel/test/SimpleJSONTest.h
+++ b/Framework/Kernel/test/SimpleJSONTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_REMOTEALGORITHMS_SIMPLEJSONTEST_H_
-#define MANTID_REMOTEALGORITHMS_SIMPLEJSONTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -235,5 +234,3 @@ const std::string SimpleJSONTest::versVal = "1";
 const std::string SimpleJSONTest::impName =
     "Implementation_Specific_Post_Variables";
 const std::string SimpleJSONTest::impVal = "example_POST_var1";
-
-#endif // MANTID_REMOTEALGORITHMS_SIMPLEJSONTEST_H_
diff --git a/Framework/Kernel/test/SobolSequenceTest.h b/Framework/Kernel/test/SobolSequenceTest.h
index 20828debaf5..0997d0cf952 100644
--- a/Framework/Kernel/test/SobolSequenceTest.h
+++ b/Framework/Kernel/test/SobolSequenceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef SOBOLSEQUENCETEST_H_
-#define SOBOLSEQUENCETEST_H_
+#pragma once
 
 #include "MantidKernel/SobolSequence.h"
 #include <cxxtest/TestSuite.h>
@@ -116,5 +115,3 @@ public:
     TS_ASSERT(sumSizes > 0);
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/SpecialCoordinateSystemTest.h b/Framework/Kernel/test/SpecialCoordinateSystemTest.h
index 77170a876d4..ccab3055e8b 100644
--- a/Framework/Kernel/test/SpecialCoordinateSystemTest.h
+++ b/Framework/Kernel/test/SpecialCoordinateSystemTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_SPECIALCOORDINATESYSTEMTEST
-#define MANTID_KERNEL_SPECIALCOORDINATESYSTEMTEST
+#pragma once
 
 #include "MantidKernel/SpecialCoordinateSystem.h"
 #include <cxxtest/TestSuite.h>
@@ -54,5 +53,3 @@ public:
     TS_ASSERT_EQUALS(3, hkl);
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/StartsWithValidatorTest.h b/Framework/Kernel/test/StartsWithValidatorTest.h
index 431016837d2..d115241d13e 100644
--- a/Framework/Kernel/test/StartsWithValidatorTest.h
+++ b/Framework/Kernel/test/StartsWithValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef STARTSWITHVALIDATORTEST_H_
-#define STARTSWITHVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -101,5 +100,3 @@ public:
     TS_ASSERT(boost::dynamic_pointer_cast<StartsWithValidator>(vv));
   }
 };
-
-#endif /*STARTSWITHVALIDATORTEST_H_*/
diff --git a/Framework/Kernel/test/StatisticsTest.h b/Framework/Kernel/test/StatisticsTest.h
index d9dd3933ae7..d51d4f48a72 100644
--- a/Framework/Kernel/test/StatisticsTest.h
+++ b/Framework/Kernel/test/StatisticsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef STATISTICSTEST_H_
-#define STATISTICSTEST_H_
+#pragma once
 
 #include "MantidKernel/Statistics.h"
 #include <algorithm>
@@ -314,5 +313,3 @@ public:
     }
   }
 };
-
-#endif // STATISTICSTEST_H_
diff --git a/Framework/Kernel/test/StdoutChannelTest.h b/Framework/Kernel/test/StdoutChannelTest.h
index c950d8adf7c..9308f7f6216 100644
--- a/Framework/Kernel/test/StdoutChannelTest.h
+++ b/Framework/Kernel/test/StdoutChannelTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_STDOUTCHANNELTEST_H_
-#define MANTID_STDOUTCHANNELTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -72,5 +71,3 @@ public:
     Poco::Logger::root().setChannel(rootChannel);
   }
 };
-
-#endif /*MANTID_STDOUTCHANNELTEST_H_*/
diff --git a/Framework/Kernel/test/StringContainsValidatorTest.h b/Framework/Kernel/test/StringContainsValidatorTest.h
index be35af842fb..2d11a413288 100644
--- a/Framework/Kernel/test/StringContainsValidatorTest.h
+++ b/Framework/Kernel/test/StringContainsValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_STRINGCONTAINSVALIDATORTEST_H_
-#define MANTID_KERNEL_STRINGCONTAINSVALIDATORTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -88,5 +87,3 @@ public:
     TS_ASSERT_EQUALS(error, validator.isValid(input));
   }
 };
-
-#endif /* MANTID_KERNEL_STRINGCONTAINSVALIDATORTEST_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/test/StringTokenizerTest.h b/Framework/Kernel/test/StringTokenizerTest.h
index 01fdab16bec..452e71bc7be 100644
--- a/Framework/Kernel/test/StringTokenizerTest.h
+++ b/Framework/Kernel/test/StringTokenizerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_STRINGTOKENIZERTEST_H_
-#define MANTID_STRINGTOKENIZERTEST_H_
+#pragma once
 
 #include "MantidKernel/StringTokenizer.h"
 #include "MantidKernel/uniform_int_distribution.h"
@@ -241,5 +240,3 @@ public:
     TS_ASSERT_EQUALS(tokenizer1.count(), m_length / 10);
   }
 };
-
-#endif // MANTID_STRINGTOKENZIERTEST_H_
diff --git a/Framework/Kernel/test/StringsTest.h b/Framework/Kernel/test/StringsTest.h
index ca17598e255..988fea1d8a3 100644
--- a/Framework/Kernel/test/StringsTest.h
+++ b/Framework/Kernel/test/StringsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_SUPPORTTEST_H_
-#define MANTID_SUPPORTTEST_H_
+#pragma once
 
 #include <Poco/Path.h>
 #include <cxxtest/TestSuite.h>
@@ -649,5 +648,3 @@ private:
   std::vector<double> input;
   std::string separator{","};
 };
-
-#endif // MANTID_SUPPORTTEST_H_
diff --git a/Framework/Kernel/test/TaskTest.h b/Framework/Kernel/test/TaskTest.h
index ba17705d7dd..46b062929b8 100644
--- a/Framework/Kernel/test/TaskTest.h
+++ b/Framework/Kernel/test/TaskTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TASKTEST_H_
-#define TASKTEST_H_
+#pragma once
 
 #include "MantidKernel/Task.h"
 #include "MantidKernel/Timer.h"
@@ -41,5 +40,3 @@ public:
     TS_ASSERT_EQUALS(mut, t.getMutex());
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/ThreadPoolRunnableTest.h b/Framework/Kernel/test/ThreadPoolRunnableTest.h
index 81180b09c15..19d4639585f 100644
--- a/Framework/Kernel/test/ThreadPoolRunnableTest.h
+++ b/Framework/Kernel/test/ThreadPoolRunnableTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADPOOLRUNNABLETEST_H_
-#define MANTID_KERNEL_THREADPOOLRUNNABLETEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/ThreadPoolRunnable.h"
@@ -85,5 +84,3 @@ public:
     TS_ASSERT_EQUALS(what, "Test exception from TaskThatThrows.");
   }
 };
-
-#endif /* MANTID_KERNEL_THREADPOOLRUNNABLETEST_H_ */
diff --git a/Framework/Kernel/test/ThreadPoolTest.h b/Framework/Kernel/test/ThreadPoolTest.h
index 9ae602e264b..c0f973bf675 100644
--- a/Framework/Kernel/test/ThreadPoolTest.h
+++ b/Framework/Kernel/test/ThreadPoolTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef THREADPOOLTEST_H_
-#define THREADPOOLTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -437,5 +436,3 @@ public:
     TS_ASSERT_EQUALS(ThreadPoolTest_TaskThatThrows_counter, 1);
   }
 };
-
-#endif
diff --git a/Framework/Kernel/test/ThreadSchedulerMutexesTest.h b/Framework/Kernel/test/ThreadSchedulerMutexesTest.h
index 2bf7befb24f..a43de116cae 100644
--- a/Framework/Kernel/test/ThreadSchedulerMutexesTest.h
+++ b/Framework/Kernel/test/ThreadSchedulerMutexesTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADSCHEDULERMUTEXESTEST_H_
-#define MANTID_KERNEL_THREADSCHEDULERMUTEXESTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -169,5 +168,3 @@ public:
     TS_ASSERT_EQUALS(sc.size(), 0);
   }
 };
-
-#endif /* MANTID_KERNEL_THREADSCHEDULERMUTEXESTEST_H_ */
diff --git a/Framework/Kernel/test/ThreadSchedulerTest.h b/Framework/Kernel/test/ThreadSchedulerTest.h
index 03a309b41de..4e141e44e79 100644
--- a/Framework/Kernel/test/ThreadSchedulerTest.h
+++ b/Framework/Kernel/test/ThreadSchedulerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_THREADSCHEDULERTEST_H_
-#define MANTID_KERNEL_THREADSCHEDULERTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -120,5 +119,3 @@ public:
     do_test(sc.get(), costs, poppedIndices);
   }
 };
-
-#endif /* MANTID_KERNEL_THREADSCHEDULERTEST_H_ */
diff --git a/Framework/Kernel/test/TimeSeriesPropertyTest.h b/Framework/Kernel/test/TimeSeriesPropertyTest.h
index 645cebfc010..b1ddbec9232 100644
--- a/Framework/Kernel/test/TimeSeriesPropertyTest.h
+++ b/Framework/Kernel/test/TimeSeriesPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TIMESERIESPROPERTYTEST_H_
-#define TIMESERIESPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/PropertyWithValue.h"
@@ -2505,5 +2504,3 @@ private:
   TimeSeriesProperty<double> *dProp;
   TimeSeriesProperty<std::string> *sProp;
 };
-
-#endif /*TIMESERIESPROPERTYTEST_H_*/
diff --git a/Framework/Kernel/test/TimeSplitterTest.h b/Framework/Kernel/test/TimeSplitterTest.h
index 4889e2f4614..21a4fb1984a 100644
--- a/Framework/Kernel/test/TimeSplitterTest.h
+++ b/Framework/Kernel/test/TimeSplitterTest.h
@@ -11,8 +11,7 @@
  *      Author: janik
  */
 
-#ifndef TIMESPLITTERTEST_H_
-#define TIMESPLITTERTEST_H_
+#pragma once
 
 #include "MantidKernel/DateAndTime.h"
 #include "MantidKernel/TimeSplitter.h"
@@ -546,5 +545,3 @@ public:
     TS_ASSERT_EQUALS(index2, 2);
   }
 };
-
-#endif /* TIMESPLITTERTEST_H_ */
diff --git a/Framework/Kernel/test/TimerTest.h b/Framework/Kernel/test/TimerTest.h
index a46ae6a507e..ed6150b09bd 100644
--- a/Framework/Kernel/test/TimerTest.h
+++ b/Framework/Kernel/test/TimerTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TIMERTEST_H_
-#define TIMERTEST_H_
+#pragma once
 
 #include "MantidKernel/Timer.h"
 #include <cxxtest/TestSuite.h>
@@ -44,5 +43,3 @@ public:
 #endif
   }
 };
-
-#endif /*TIMERTEST_H_*/
diff --git a/Framework/Kernel/test/TopicInfoTest.h b/Framework/Kernel/test/TopicInfoTest.h
index b97d391a6e8..15caa3a3bcc 100644
--- a/Framework/Kernel/test/TopicInfoTest.h
+++ b/Framework/Kernel/test/TopicInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TOPICINFOTEST_H_
-#define MANTID_KERNEL_TOPICINFOTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -73,5 +72,3 @@ private:
     return new FacilityInfo(elem);
   }
 };
-
-#endif /* MANTID_KERNEL_TOPICINFOTEST_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/test/TypedValidatorTest.h b/Framework/Kernel/test/TypedValidatorTest.h
index 728d8484999..af1f4113b1a 100644
--- a/Framework/Kernel/test/TypedValidatorTest.h
+++ b/Framework/Kernel/test/TypedValidatorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_TYPEDVALIDATORTEST_H_
-#define MANTID_KERNEL_TYPEDVALIDATORTEST_H_
+#pragma once
 
 #include "MantidKernel/DataItem.h"
 #include "MantidKernel/TypedValidator.h"
@@ -77,5 +76,3 @@ private:
     TS_ASSERT_EQUALS(error, "");
   }
 };
-
-#endif /* MANTID_KERNEL_TYPEDVALIDATORTEST_H_ */
diff --git a/Framework/Kernel/test/UnitConversionTest.h b/Framework/Kernel/test/UnitConversionTest.h
index 812100fd57d..7f16ef00e39 100644
--- a/Framework/Kernel/test/UnitConversionTest.h
+++ b/Framework/Kernel/test/UnitConversionTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITCONVERTERTEST_H_
-#define MANTID_KERNEL_UNITCONVERTERTEST_H_
+#pragma once
 
 #include "MantidKernel/Exception.h"
 #include "MantidKernel/PhysicalConstants.h"
@@ -74,5 +73,3 @@ public:
     TS_ASSERT_DELTA(result, expected, 1e-12);
   }
 };
-
-#endif /* MANTID_KERNEL_UNITCONVERTERTEST_H_ */
diff --git a/Framework/Kernel/test/UnitFactoryTest.h b/Framework/Kernel/test/UnitFactoryTest.h
index 961c398660c..3d4ef0abd49 100644
--- a/Framework/Kernel/test/UnitFactoryTest.h
+++ b/Framework/Kernel/test/UnitFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef UNITFACTORYTEST_H_
-#define UNITFACTORYTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -46,5 +45,3 @@ public:
                std::find(keys.begin(), keys.end(), "TOF") != keys.end());
   }
 };
-
-#endif /*UNITFACTORYTEST_H_*/
diff --git a/Framework/Kernel/test/UnitLabelTest.h b/Framework/Kernel/test/UnitLabelTest.h
index 4fa25b272b2..2ff9e61b439 100644
--- a/Framework/Kernel/test/UnitLabelTest.h
+++ b/Framework/Kernel/test/UnitLabelTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UNITLABELTEST_H_
-#define MANTID_KERNEL_UNITLABELTEST_H_
+#pragma once
 
 #include "MantidKernel/UnitLabel.h"
 
@@ -77,5 +76,3 @@ private:
     TS_ASSERT_EQUALS(std::wstring(expected.begin(), expected.end()), utf8);
   }
 };
-
-#endif /* MANTID_KERNEL_UNITLABELTEST_H_ */
diff --git a/Framework/Kernel/test/UnitTest.h b/Framework/Kernel/test/UnitTest.h
index 769667c20d4..17e5dda8552 100644
--- a/Framework/Kernel/test/UnitTest.h
+++ b/Framework/Kernel/test/UnitTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef UNITTEST_H_
-#define UNITTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -1537,5 +1536,3 @@ private:
   Units::Temperature temperature;
   Units::AtomicDistance atomicDistance;
 };
-
-#endif /*UNITTEST_H_*/
diff --git a/Framework/Kernel/test/UsageServiceTest.h b/Framework/Kernel/test/UsageServiceTest.h
index 3c3b8c8e952..2e035187ec1 100644
--- a/Framework/Kernel/test/UsageServiceTest.h
+++ b/Framework/Kernel/test/UsageServiceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_API_USAGESERVICETEST_H_
-#define MANTID_API_USAGESERVICETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -180,5 +179,3 @@ public:
     TS_ASSERT_EQUALS(usageService.getApplicationName(), name);
   }
 };
-
-#endif /* MANTID_API_USAGESERVICETEST_H_ */
\ No newline at end of file
diff --git a/Framework/Kernel/test/UserCatalogInfoTest.h b/Framework/Kernel/test/UserCatalogInfoTest.h
index fcbd4587ef7..74b2828042b 100644
--- a/Framework/Kernel/test/UserCatalogInfoTest.h
+++ b/Framework/Kernel/test/UserCatalogInfoTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_USERCATALOGINFOTEST_H_
-#define MANTID_KERNEL_USERCATALOGINFOTEST_H_
+#pragma once
 
 #include "MantidKernel/ICatalogInfo.h"
 #include "MantidKernel/UserCatalogInfo.h"
@@ -193,5 +192,3 @@ public:
     delete service;
   }
 };
-
-#endif /* MANTID_KERNEL_USERCATALOGINFOTEST_H_ */
diff --git a/Framework/Kernel/test/UserStringParserTest.h b/Framework/Kernel/test/UserStringParserTest.h
index 2703d01fdb4..31679364b59 100644
--- a/Framework/Kernel/test/UserStringParserTest.h
+++ b/Framework/Kernel/test/UserStringParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef RANGESTRINGPARSERTEST_H_
-#define RANGESTRINGPARSERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -164,5 +163,3 @@ public:
 
 private:
 };
-
-#endif
diff --git a/Framework/Kernel/test/UtilsTest.h b/Framework/Kernel/test/UtilsTest.h
index b115b7fe712..ee62c59ae6b 100644
--- a/Framework/Kernel/test/UtilsTest.h
+++ b/Framework/Kernel/test/UtilsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_UTILSTEST_H_
-#define MANTID_KERNEL_UTILSTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -193,5 +192,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_KERNEL_UTILSTEST_H_ */
diff --git a/Framework/Kernel/test/V2DTest.h b/Framework/Kernel/test/V2DTest.h
index 1ae1bbc10ec..44edc3f0843 100644
--- a/Framework/Kernel/test/V2DTest.h
+++ b/Framework/Kernel/test/V2DTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_V2DTEST_H_
-#define MANTID_KERNEL_V2DTEST_H_
+#pragma once
 
 //-----------------------------------------------------------------------------
 // Includes
@@ -216,5 +215,3 @@ public:
     TS_ASSERT(first != second);
   }
 };
-
-#endif // MANTID_KERNEL_V2DTEST_H_
diff --git a/Framework/Kernel/test/V3DTest.h b/Framework/Kernel/test/V3DTest.h
index 7bedef857b5..aa7729a4177 100644
--- a/Framework/Kernel/test/V3DTest.h
+++ b/Framework/Kernel/test/V3DTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_TESTV3D__
-#define MANTID_TESTV3D__
+#pragma once
 
 #include <cmath>
 #include <cxxtest/TestSuite.h>
@@ -799,5 +798,3 @@ private:
   Mantid::Kernel::Matrix<double> m_rotx;
   size_t m_sampleSize;
 };
-
-#endif
diff --git a/Framework/Kernel/test/VMDTest.h b/Framework/Kernel/test/VMDTest.h
index 70d7cf17795..811081e335e 100644
--- a/Framework/Kernel/test/VMDTest.h
+++ b/Framework/Kernel/test/VMDTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VMDTEST_H_
-#define MANTID_KERNEL_VMDTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -219,5 +218,3 @@ public:
     TS_ASSERT_EQUALS(normal, VMD(1., -1., 0., 0.) * sqrt(0.5));
   }
 };
-
-#endif /* MANTID_KERNEL_VMDTEST_H_ */
diff --git a/Framework/Kernel/test/VectorHelperTest.h b/Framework/Kernel/test/VectorHelperTest.h
index dddb116d46e..30092dcec1d 100644
--- a/Framework/Kernel/test/VectorHelperTest.h
+++ b/Framework/Kernel/test/VectorHelperTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VECTORHELPERTEST_H_
-#define MANTID_KERNEL_VECTORHELPERTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -611,5 +610,3 @@ private:
       largerBinEdges[i] = binEdges[(2 * i)];
   }
 };
-
-#endif /* MANTID_KERNEL_VECTORHELPERTEST_H_ */
diff --git a/Framework/Kernel/test/VisibleWhenPropertyTest.h b/Framework/Kernel/test/VisibleWhenPropertyTest.h
index 0f2d7167d0b..4babc40197b 100644
--- a/Framework/Kernel/test/VisibleWhenPropertyTest.h
+++ b/Framework/Kernel/test/VisibleWhenPropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_VISIBLEWHENPROPERTYTEST_H_
-#define MANTID_KERNEL_VISIBLEWHENPROPERTYTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -225,5 +224,3 @@ private:
                                                  logicalOperator);
   }
 };
-
-#endif /* MANTID_KERNEL_VISIBLEWHENPROPERTYTEST_H_ */
diff --git a/Framework/Kernel/test/WriteLockTest.h b/Framework/Kernel/test/WriteLockTest.h
index c910c5d8507..7f8d51da020 100644
--- a/Framework/Kernel/test/WriteLockTest.h
+++ b/Framework/Kernel/test/WriteLockTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_KERNEL_WRITELOCKTEST_H_
-#define MANTID_KERNEL_WRITELOCKTEST_H_
+#pragma once
 
 #include "MantidKernel/WriteLock.h"
 
@@ -44,5 +43,3 @@ public:
     //    WriteLock * lock = new WriteLock(item);
   }
 };
-
-#endif /* MANTID_KERNEL_READLOCKTEST_H_ */
-- 
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