diff --git a/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameter.h b/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameter.h
index ba6be205ae4c151cf9370ab2a98ba5301ae9f2b2..409263b6b61c6cfbd146f1da18276a32c77d329e 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameter.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_AFFINE_MATRIX_PARAMETER
-#define MANTID_DATAOBJECTS_AFFINE_MATRIX_PARAMETER
+#pragma once
 
 #include "MantidAPI/ImplicitFunctionParameter.h"
 #include "MantidGeometry/MDGeometry/MDTypes.h"
@@ -58,5 +57,3 @@ private:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameterParser.h b/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameterParser.h
index 4410d6896a17880c0376e8b5759d3da12ef7431f..e28ad70151b733759125fd723848bc2b38ff986c 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameterParser.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/AffineMatrixParameterParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_AFFINE_MATRIX_PARAMETER_PARSER
-#define MANTID_DATAOBJECTS_AFFINE_MATRIX_PARAMETER_PARSER
+#pragma once
 
 #include "MantidAPI/ImplicitFunctionParameterParser.h"
 #include "MantidDataObjects/AffineMatrixParameter.h"
@@ -40,5 +39,3 @@ private:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/BoxControllerNeXusIO.h b/Framework/DataObjects/inc/MantidDataObjects/BoxControllerNeXusIO.h
index 61af02a39d9795f20fda6f49e9e326d0c5895080..78990306fe241a79389815b5e0c7a0633bc288ef 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/BoxControllerNeXusIO.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/BoxControllerNeXusIO.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_BOXCONTROLLER_NEXUSS_IO_H
-#define MANTID_DATAOBJECTS_BOXCONTROLLER_NEXUSS_IO_H
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidAPI/IBoxControllerIO.h"
@@ -148,5 +147,4 @@ private:
                         const size_t nPoints) const;
 };
 } // namespace DataObjects
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometry.h b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometry.h
index 33549b6bd4ece419f05fcd7a74b6273942e0cd1f..46b96c407af6c9939afeca27cd3a0da66687bee3 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometry.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometry.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRY_H_
-#define MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRY_H_
+#pragma once
 
 #include "MantidGeometry/Math/Quadrilateral.h"
 #include <cmath>
@@ -55,5 +54,3 @@ public:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryKiKf.h b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryKiKf.h
index 3afcd87e75af6285ef8262f0771f420f13113544..bfbbabe3bab985f6abada5c7eaa0fae9a04967d1 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryKiKf.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryKiKf.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYKIKF_H_
-#define MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYKIKF_H_
+#pragma once
 #include "MantidDataObjects/CalculateReflectometry.h"
 
 namespace Mantid {
@@ -91,5 +90,4 @@ public:
   }
 };
 } // namespace DataObjects
-} // namespace Mantid
-#endif // MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYKIKF_H_
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryP.h b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryP.h
index 89e5d06116a1b0627ed9e2014a24c20d1a32836a..fa14354b3724a302f940ed9b35b0ad3cc8ed94b2 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryP.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryP.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYP_H_
-#define MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYP_H_
+#pragma once
 
 #include "MantidDataObjects/CalculateReflectometry.h"
 
@@ -98,5 +97,4 @@ public:
   }
 };
 } // namespace DataObjects
-} // namespace Mantid
-#endif // MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYP_H_
\ No newline at end of file
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryQxQz.h b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryQxQz.h
index 1ae58aed38f228d1be7dba18997b3ce4b2ed6e5b..53d9dc653126d9167e1d3f44cee20c9431b586a1 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryQxQz.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CalculateReflectometryQxQz.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYQXQZ_H_
-#define MANTID_DATAOBJECTS_CALCULATEREFLECTOMETRYQXQZ_H_
+#pragma once
 
 #include "MantidDataObjects/CalculateReflectometry.h"
 
@@ -100,5 +99,3 @@ public:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffine.h b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffine.h
index 124c02b74f8ea06da91c47f7ce55af1e9b15e722..d9df4eb9f086809bb17bc1bf53ba29d31d9a4ab0 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffine.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffine.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMAFFINE_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMAFFINE_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidAPI/SingleValueParameter.h"
@@ -77,5 +76,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMAFFINE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffineParser.h b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffineParser.h
index cfcc387679fe2586fa5a1fcef432fcf8cec1c70d..33d48e0a1aaffd88228a42f3c7b53a7abb676817 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffineParser.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAffineParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMPARSER_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMPARSER_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <boost/shared_ptr.hpp>
@@ -50,5 +49,3 @@ private:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAligned.h b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAligned.h
index b50e5e60b4cd00658d3d2ac68c18e981137c793c..9ec2a3f4cf2ae11ce3ef8bea76fcc9475e05e7ea 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAligned.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformAligned.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMALIGNED_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMALIGNED_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidAPI/VectorParameter.h"
@@ -64,5 +63,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMALIGNED_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistance.h b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistance.h
index 1449321ddcd2a64093bbc9661118cff74c7a427b..76c0e73a7d9415c770d0d4dd0b401ff61659c5f2 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistance.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistance.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCE_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCE_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidAPI/VectorParameter.h"
@@ -65,5 +64,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistanceParser.h b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistanceParser.h
index f80cff669abb7a2691fd01c15beb21e6fc847f92..cc8b6c21ff9756186964a6f4aaf426b7ea8fa68a 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistanceParser.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/CoordTransformDistanceParser.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCEPARSER_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCEPARSER_H_
+#pragma once
 
 #include "MantidDataObjects/CoordTransformAffineParser.h"
 #include "MantidKernel/System.h"
@@ -34,5 +33,3 @@ private:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/DllConfig.h b/Framework/DataObjects/inc/MantidDataObjects/DllConfig.h
index 368dc0d7f62588408849e0e96d3651d14d85b501..9eb5149000e359afe25298ec534ef00e7ead8c6e 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/DllConfig.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/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_DATAOBJECTS_DLLCONFIG_H_
-#define MANTID_DATAOBJECTS_DLLCONFIG_H_
+#pragma once
 
 /*
     This file contains the DLLExport/DLLImport linkage configuration for the
@@ -22,5 +21,3 @@
 #define MANTID_DATAOBJECTS_DLL DLLImport
 #define EXTERN_MANTID_DATAOBJECTS EXTERN_IMPORT
 #endif /* IN_MANTID_DATAOBJECTS*/
-
-#endif // MANTID_DATAOBJECTS_DLLCONFIG_H_
diff --git a/Framework/DataObjects/inc/MantidDataObjects/EventList.h b/Framework/DataObjects/inc/MantidDataObjects/EventList.h
index 86ef07c9c0ca26bb201a91f0e4e080e024980890..6eacecaac6f4654cb0d014018cf7e04e6a40c5bc 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/EventList.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/EventList.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_EVENTLIST_H_
-#define MANTID_DATAOBJECTS_EVENTLIST_H_ 1
+#pragma once
 
 #include "MantidAPI/IEventList.h"
 #include "MantidDataObjects/Events.h"
@@ -565,5 +564,4 @@ DLLExport void getEventsFrom(const EventList &el,
                              std::vector<WeightedEventNoTime> const *&events);
 
 } // namespace DataObjects
-} // namespace Mantid
-#endif /// MANTID_DATAOBJECTS_EVENTLIST_H_
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspace.h
index 6659cd472643d72c6200ab648e97e4410aa51f8c..dfea169327480637c2466de488e634259ea52778 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_EVENTWORKSPACE_H_
-#define MANTID_DATAOBJECTS_EVENTWORKSPACE_H_ 1
+#pragma once
 
 #include "MantidAPI/IEventWorkspace.h"
 #include "MantidAPI/ISpectrum.h"
@@ -183,5 +182,3 @@ using EventWorkspace_const_sptr = boost::shared_ptr<const EventWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_EVENTWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceHelpers.h b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceHelpers.h
index f00dd36c69c4e47df65ad6fce483975f28516555..86ef7b8cb73cc0c4256a005a7f6602668d96857c 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceHelpers.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceHelpers.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef EVENTWORKSPACEHELPERS_H_
-#define EVENTWORKSPACEHELPERS_H_
+#pragma once
 
 #include "MantidAPI/MatrixWorkspace_fwd.h"
 #include "MantidDataObjects/EventWorkspace.h"
@@ -26,5 +25,3 @@ struct DLLExport EventWorkspaceHelpers {
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* EVENTWORKSPACEHELPERS_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceMRU.h b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceMRU.h
index ceb34ab5cad2fde2d7c4d2e92eb76847b45fc2b0..e89acfd1d24f85de450ce97eb2a67ae7951d62bf 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceMRU.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/EventWorkspaceMRU.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_EVENTWORKSPACEMRU_H_
-#define MANTID_DATAOBJECTS_EVENTWORKSPACEMRU_H_
+#pragma once
 
 #include "MantidHistogramData/HistogramE.h"
 #include "MantidHistogramData/HistogramY.h"
@@ -102,5 +101,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_EVENTWORKSPACEMRU_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/Events.h b/Framework/DataObjects/inc/MantidDataObjects/Events.h
index 434577ebff9f9126a59e52629b1aa8542a842d4c..5b475b86c4c421dec3387f29d8f362caf6c6cc8c 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/Events.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/Events.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_EVENTS_H_
-#define MANTID_DATAOBJECTS_EVENTS_H_
+#pragma once
 
 #ifdef _WIN32 /* _WIN32 */
 #include <time.h>
@@ -218,5 +217,4 @@ inline double WeightedEventNoTime::errorSquared() const {
 }
 
 } // namespace DataObjects
-} // namespace Mantid
-#endif /// MANTID_DATAOBJECTS_EVENTS_H_
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/FakeMD.h b/Framework/DataObjects/inc/MantidDataObjects/FakeMD.h
index 08abe20924ed8119eac99928f275a2db6ee25a38..e4dd36d0a8a61a4512dec71cb7cb24abf74d80b6 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/FakeMD.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/FakeMD.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_FAKEMD_H_
-#define MANTID_DATAOBJECTS_FAKEMD_H_
+#pragma once
 
 #include <vector>
 
@@ -57,5 +56,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_FAKEMD_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/FractionalRebinning.h b/Framework/DataObjects/inc/MantidDataObjects/FractionalRebinning.h
index 6bf685879efb01964daafd16d8628848d658894f..cfd77a428bf86d4aead981895481d830eddcd4f3 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/FractionalRebinning.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/FractionalRebinning.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_FRACTIONALREBINNING_
-#define MANTID_DATAOBJECTS_FRACTIONALREBINNING_
+#pragma once
 
 //------------------------------------------------------------------------------
 // Includes
@@ -70,5 +69,3 @@ finalizeFractionalRebin(DataObjects::RebinnedOutput &outputWS);
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
diff --git a/Framework/DataObjects/inc/MantidDataObjects/GroupingWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/GroupingWorkspace.h
index b78d60d1ea263fd2b46885bc981a5d55a0b6dfb3..47ca58aaf770a7fb064d5b826657765ea673866b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/GroupingWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/GroupingWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_GROUPINGWORKSPACE_H_
-#define MANTID_DATAOBJECTS_GROUPINGWORKSPACE_H_
+#pragma once
 
 #include "MantidAPI/MatrixWorkspace_fwd.h"
 #include "MantidDataObjects/SpecialWorkspace2D.h"
@@ -71,5 +70,3 @@ using GroupingWorkspace_const_sptr = boost::shared_ptr<const GroupingWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_GROUPINGWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/Histogram1D.h b/Framework/DataObjects/inc/MantidDataObjects/Histogram1D.h
index e5691092d4767f7ea1a39d598092843d384c5f12..52c6c9d74473bd8ed548016fb8b8203035ffe5f6 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/Histogram1D.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/Histogram1D.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_HISTOGRAM1D_H_
-#define MANTID_DATAOBJECTS_HISTOGRAM1D_H_
+#pragma once
 
 #include "MantidAPI/ISpectrum.h"
 #include "MantidKernel/System.h"
@@ -85,5 +84,4 @@ private:
 };
 
 } // namespace DataObjects
-} // Namespace Mantid
-#endif /*MANTID_DATAOBJECTS_HISTOGRAM1D_H_*/
+} // Namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBin.h b/Framework/DataObjects/inc/MantidDataObjects/MDBin.h
index 650be10f1cc9a86e2130ebaa4a2405409312ccd3..c6e59f13d750d82adc19e7354bfbf11cb42e3d0b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBin.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBin.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBIN_H_
-#define MANTID_DATAOBJECTS_MDBIN_H_
+#pragma once
 
 #include "MantidDataObjects/MDLeanEvent.h"
 #include "MantidGeometry/MDGeometry/IMDDimension.h"
@@ -57,5 +56,3 @@ public:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDBIN_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBox.h b/Framework/DataObjects/inc/MantidDataObjects/MDBox.h
index f388be250ac1dcab5f11d8ca7af9a0efd1477d62..68a99e1f131efac3ba2c95b5ef20f2d1ad136692 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBox.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBox.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDBOX_H_
-#define MDBOX_H_
+#pragma once
 
 #include "MantidAPI/IMDWorkspace.h"
 #include "MantidDataObjects/MDBoxBase.h"
@@ -300,5 +299,3 @@ public:
 } // namespace DataObjects
 
 } // namespace Mantid
-
-#endif /* MDBOX_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBoxBase.h b/Framework/DataObjects/inc/MantidDataObjects/MDBoxBase.h
index 1dc0a5b00227c045bcaadc5c7e2e774abfa6dba0..f551613b3336ad6649021fd62304437df5d2a2b7 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBoxBase.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBoxBase.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDBOXBASE_H_
-#define MDBOXBASE_H_
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidAPI/CoordTransform.h"
@@ -430,5 +429,3 @@ void MDBoxBase<MDE, nd>::calcCaches(const EventIterator &begin,
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MDBOXBASE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBoxFlatTree.h b/Framework/DataObjects/inc/MantidDataObjects/MDBoxFlatTree.h
index 88799a4f641f6ec7f8b47c9c02b1452294ce9f7f..db407f34e4aa6911e64f64907e23f8528c8cbba3 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBoxFlatTree.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBoxFlatTree.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDBOX_FLAT_TREE_H_
-#define MDBOX_FLAT_TREE_H_
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidDataObjects/MDBox.h"
@@ -141,5 +140,4 @@ template <typename T>
 void saveMatrix(::NeXus::File *const file, std::string name,
                 Kernel::Matrix<T> &m, ::NeXus::NXnumtype type, std::string tag);
 } // namespace DataObjects
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBoxIterator.h b/Framework/DataObjects/inc/MantidDataObjects/MDBoxIterator.h
index 4fd0affa4f7f979b5f06465879e645d596ee84ef..8a82ee2519061bbd694a2f59fac963e36c143b56 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBoxIterator.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBoxIterator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBOXITERATOR_H_
-#define MANTID_DATAOBJECTS_MDBOXITERATOR_H_
+#pragma once
 
 #include "MantidAPI/IMDIterator.h"
 #include "MantidDataObjects/MDBox.h"
@@ -127,5 +126,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDBOXITERATOR_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBoxSaveable.h b/Framework/DataObjects/inc/MantidDataObjects/MDBoxSaveable.h
index 7e7df54002df3f2cbfb9cc4efe0d148aa215c23d..50e8b27fa9c4b845f4d6b29c314e7b4c7f37c9c7 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBoxSaveable.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBoxSaveable.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBOX_SAVEABLE_H
-#define MANTID_DATAOBJECTS_MDBOX_SAVEABLE_H
+#pragma once
 
 #include "MantidAPI/IMDNode.h"
 #include "MantidKernel/ISaveable.h"
@@ -54,5 +53,3 @@ private:
 };
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDDimensionStats.h b/Framework/DataObjects/inc/MantidDataObjects/MDDimensionStats.h
index d95bf1e9da2dc1955975b9aa9b96245903acdc03..53a137cad91bed16def52320b9e430f7b12949ff 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDDimensionStats.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDDimensionStats.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDDIMENSIONSTATS_H_
-#define MANTID_DATAOBJECTS_MDDIMENSIONSTATS_H_
+#pragma once
 
 #include "MantidDataObjects/MDLeanEvent.h"
 #include "MantidKernel/System.h"
@@ -68,5 +67,3 @@ public:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDDIMENSIONSTATS_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDEvent.h b/Framework/DataObjects/inc/MantidDataObjects/MDEvent.h
index b928c2023e00037897028f7d42d940681eef3781..9504f7b2fa65a131143a53db76d861240f30e2dc 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDEvent.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDEvent.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDEVENT_H_
-#define MDEVENT_H_
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidDataObjects/MDLeanEvent.h"
@@ -263,5 +262,3 @@ public:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MDEVENT_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDEventFactory.h b/Framework/DataObjects/inc/MantidDataObjects/MDEventFactory.h
index aaf847c8547e8c9d91430d5b7af430fe8beb59c8..1db791c8034b89b6673736b41421236158ddd8a7 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDEventFactory.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDEventFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDEVENTFACTORY_H_
-#define MANTID_DATAOBJECTS_MDEVENTFACTORY_H_
+#pragma once
 
 #include "MantidAPI/IMDEventWorkspace_fwd.h"
 
@@ -631,5 +630,3 @@ using MDBin9 = MDBin<MDEvent<9>, 9>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDEVENTFACTORY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDEventInserter.h b/Framework/DataObjects/inc/MantidDataObjects/MDEventInserter.h
index a905f6a34410a88116aaaa069a88c78bee14c26d..b41b622f147646b62f902eaebad41e3447d5eab4 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDEventInserter.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDEventInserter.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDEVENTINSERTER_H_
-#define MANTID_DATAOBJECTS_MDEVENTINSERTER_H_
+#pragma once
 
 #include "MantidGeometry/MDGeometry/MDTypes.h"
 #include "MantidKernel/System.h"
@@ -92,5 +91,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDEVENTINSERTER_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDEventWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/MDEventWorkspace.h
index b7567ae9edf1c294299ee6df207d9e8889a7c06a..d9e25022e65123cc3ff1ae4a702f5eeed817d095 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDEventWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDEventWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDEVENTWORKSPACE_H_
-#define MDEVENTWORKSPACE_H_
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidAPI/IMDEventWorkspace.h"
@@ -261,5 +260,3 @@ private:
 } // namespace DataObjects
 
 } // namespace Mantid
-
-#endif /* MDEVENTWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDFramesToSpecialCoordinateSystem.h b/Framework/DataObjects/inc/MantidDataObjects/MDFramesToSpecialCoordinateSystem.h
index dfcba2db14967b5d81b619374d26492ed342fae7..e6661600d8a180c6b337fd52a684529fe2813ddd 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDFramesToSpecialCoordinateSystem.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDFramesToSpecialCoordinateSystem.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDFRAMESTOSPECIALCOORDINATESYTEM_H_
-#define MANTID_DATAOBJECTS_MDFRAMESTOSPECIALCOORDINATESYTEM_H_
+#pragma once
 
 #include "MantidAPI/IMDWorkspace.h"
 #include "MantidGeometry/MDGeometry/IMDDimension.h"
@@ -34,5 +33,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDFRAMESTOSPECIALCOORDINATESYTEM_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDGridBox.h b/Framework/DataObjects/inc/MantidDataObjects/MDGridBox.h
index 97c7f1587eaae15fd33775f034096a6602b9cdaf..2c1a61f561f01327882335acfe6e7bfced5ce7f3 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDGridBox.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDGridBox.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDGRIDBOX_H_
-#define MDGRIDBOX_H_
+#pragma once
 
 #include "MantidAPI/IMDWorkspace.h"
 #include "MantidDataObjects/MDBox.h"
@@ -272,5 +271,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MDGRIDBOX_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspace.h
index f681a3162e6fffde9e7acdbf5ac5c8d13f470a68..1613dde1695d46a8d4ded58556696eb16502bcf0 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDHISTOWORKSPACE_H_
-#define MANTID_DATAOBJECTS_MDHISTOWORKSPACE_H_
+#pragma once
 
 #include "MantidAPI/IMDHistoWorkspace.h"
 #include "MantidAPI/IMDIterator.h"
@@ -533,5 +532,3 @@ using MDHistoWorkspace_const_sptr = boost::shared_ptr<const MDHistoWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDHISTOWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspaceIterator.h b/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspaceIterator.h
index e13c043b9f47e70ec88fe986a7d1a206e2282e8f..7bea2657b52357eba272890d522e1a3483ffaef1 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspaceIterator.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDHistoWorkspaceIterator.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATOR_H_
-#define MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATOR_H_
+#pragma once
 
 #include "MantidAPI/IMDIterator.h"
 #include "MantidDataObjects/MDHistoWorkspace.h"
@@ -179,5 +178,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATOR_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDLeanEvent.h b/Framework/DataObjects/inc/MantidDataObjects/MDLeanEvent.h
index 8036afabdca7c0926a097f52808e9597e145b0cc..eff0ce487ed0cc77761cac6f98629f776bb777af 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDLeanEvent.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDLeanEvent.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDLEANEVENT_H_
-#define MANTID_DATAOBJECTS_MDLEANEVENT_H_
+#pragma once
 
 #include "MantidDataObjects/MortonIndex/BitInterleaving.h"
 #include "MantidDataObjects/MortonIndex/CoordinateConversion.h"
@@ -414,5 +413,3 @@ void swap(MDLeanEvent<ND> &first, MDLeanEvent<ND> &second) {
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_MDLEANEVENT_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MaskWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/MaskWorkspace.h
index 5710ce695e274f88a63f47bf62b416b8d0924e73..f4996b3076f439ff9adc37cd3ef0d0fe80eb8eab 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MaskWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MaskWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MASKWORKSPACE_H
-#define MANTID_DATAOBJECTS_MASKWORKSPACE_H
+#pragma once
 
 #include "MantidAPI/IMaskWorkspace.h"
 #include "MantidAPI/MatrixWorkspace_fwd.h"
@@ -77,5 +76,3 @@ using MaskWorkspace_const_sptr = boost::shared_ptr<const MaskWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif // MANTID_DATAOBJECTS_MASKWORKSPACE_H
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/BitInterleaving.h b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/BitInterleaving.h
index 916696dde2a4d81513fc8c5ff54fe4272e850ed5..2d2a2f7e30102459a94498b17282f879a35396bb 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/BitInterleaving.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/BitInterleaving.h
@@ -5,8 +5,7 @@
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
 
-#ifndef MANTID_DATAOBJECTS_MORTONINDEX_BITINTERLEAVING_H_
-#define MANTID_DATAOBJECTS_MORTONINDEX_BITINTERLEAVING_H_
+#pragma once
 
 #include <cinttypes>
 #include <cstddef>
@@ -351,5 +350,4 @@ template <size_t ND, typename IntT> struct Interleaver<ND, IntT, Morton96> {
   }
 };
 
-} // namespace morton_index
-#endif // MANTID_DATAOBJECTS_MORTONINDEX_BITINTERLEAVING_H_
\ No newline at end of file
+} // namespace morton_index
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/CoordinateConversion.h b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/CoordinateConversion.h
index 47eb2985386ad147be13fb8fc592fbe3d1a90d40..1fd858b9ef37f01814cf79d9d2637b05a6782543 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/CoordinateConversion.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/CoordinateConversion.h
@@ -5,8 +5,7 @@
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
 
-#ifndef MANTID_DATAOBJECTS_MORTONINDEX_COORDINATE_CONVERSION_H_
-#define MANTID_DATAOBJECTS_MORTONINDEX_COORDINATE_CONVERSION_H_
+#pragma once
 
 #include "Types.h"
 #include <algorithm>
@@ -163,5 +162,3 @@ MortonT coordinatesToIndex(coord_t *coord, const MDSpaceBounds<nd> &space) {
 }
 
 } // namespace morton_index
-
-#endif // MANTID_DATAOBJECTS_MORTONINDEX_COORDINATE_CONVERSION_H_
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/Types.h b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/Types.h
index 12725f86c45bc04a241db830924f35066200a27a..2a61cc9fce7e0d1c0ff554f465a77b986da22d48 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/Types.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/MortonIndex/Types.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MORTONINDEX_TYPES_H_
-#define MANTID_DATAOBJECTS_MORTONINDEX_TYPES_H_
+#pragma once
 
 // boost::multiprecision is not used here because the
 // with of the number is one WORD bigger, than actual
@@ -93,5 +92,4 @@ template <size_t ND, typename FP> struct IndexTypes {
   using IntType = typename UnderlyingInt<FP>::type;
 };
 
-} // namespace morton_index
-#endif // MANTID_DATAOBJECTS_MORTONINDEX_TYPES_H_
+} // namespace morton_index
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/NoShape.h b/Framework/DataObjects/inc/MantidDataObjects/NoShape.h
index 44d49a4180a725588d2c6adebcdc629745fca974..3194f966411609eb9bb0d8a0496ce3a97ff04004 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/NoShape.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/NoShape.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_NOSHAPE_H_
-#define MANTID_DATAOBJECTS_NOSHAPE_H_
+#pragma once
 
 #include "MantidGeometry/Crystal/PeakShape.h"
 #include "MantidKernel/System.h"
@@ -39,5 +38,3 @@ public:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_NOSHAPE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/OffsetsWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/OffsetsWorkspace.h
index b0d76e320adb5e82a25714390460a3bc790257d2..fc19f82d2c4e95b9ea56210653a85d9b046b78fb 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/OffsetsWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/OffsetsWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_OFFSETSWORKSPACE_H_
-#define MANTID_DATAOBJECTS_OFFSETSWORKSPACE_H_
+#pragma once
 
 #include "MantidAPI/MatrixWorkspace_fwd.h"
 #include "MantidDataObjects/SpecialWorkspace2D.h"
@@ -61,5 +60,3 @@ using OffsetsWorkspace_const_sptr = boost::shared_ptr<const OffsetsWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_OFFSETSWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/Peak.h b/Framework/DataObjects/inc/MantidDataObjects/Peak.h
index dc59dd5a24bad7166ff06b9580a67c9f289f8800..c0d1a01e08519c858b50ec85bf9b2f1e43dd71f4 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/Peak.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/Peak.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAK_H_
-#define MANTID_DATAOBJECTS_PEAK_H_
+#pragma once
 
 #include "MantidGeometry/Crystal/IPeak.h"
 #include "MantidGeometry/Crystal/PeakShape.h"
@@ -272,5 +271,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAK_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakColumn.h b/Framework/DataObjects/inc/MantidDataObjects/PeakColumn.h
index 008272d18852d865a11a7a8262fee1c627f922c6..f3895ebbeacd1b6527254534a5fb961ed46724d8 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakColumn.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakColumn.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKCOLUMN_H_
-#define MANTID_DATAOBJECTS_PEAKCOLUMN_H_
+#pragma once
 
 #include "MantidAPI/Column.h"
 #include "MantidDataObjects/Peak.h"
@@ -105,5 +104,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKCOLUMN_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakNoShapeFactory.h b/Framework/DataObjects/inc/MantidDataObjects/PeakNoShapeFactory.h
index e5edfd22d84807a75aab10e7736f91cbe60c6a15..2d9c564a9fd1b376f65b1e157eafe6de0cc3d845 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakNoShapeFactory.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakNoShapeFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORY_H_
-#define MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORY_H_
+#pragma once
 
 #include "MantidDataObjects/PeakShapeFactory.h"
 #include "MantidKernel/System.h"
@@ -31,5 +30,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeBase.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeBase.h
index e3005ebc0a6c0668f3f72b2b85debbf5698273d0..74dd0faabe916fc8e7851ea18b453cf861ef1d7d 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeBase.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeBase.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEBASE_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEBASE_H_
+#pragma once
 
 #include "MantidGeometry/Crystal/PeakShape.h"
 #include "MantidKernel/SpecialCoordinateSystem.h"
@@ -63,5 +62,3 @@ protected:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEBASE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoid.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoid.h
index f50ec0596d27c4634117555c5d82493ff291c3ef..d9665a824a8efc937cb9bf201e24f249e3cdb192 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoid.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoid.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOID_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOID_H_
+#pragma once
 
 #include "MantidDataObjects/PeakShapeBase.h"
 #include "MantidKernel/Matrix.h"
@@ -70,5 +69,3 @@ using PeakShapeEllipsoid_const_sptr =
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOID_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoidFactory.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoidFactory.h
index 27190bd8979c53427c6cc144d1a38d0f2362d721..7ec54e891eefd133f7b6a8a47b779cae607b7a6e 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoidFactory.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeEllipsoidFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORY_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORY_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "PeakShapeFactory.h"
@@ -30,5 +29,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeFactory.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeFactory.h
index e3f2c168fff7f9843ae4933bc0126c1f712c1b90..f4b281a6377f8019f40358bf90a0928c2181332b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeFactory.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEFACTORY_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEFACTORY_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include <boost/shared_ptr.hpp>
@@ -39,5 +38,3 @@ using PeakShapeFactory_const_sptr = boost::shared_ptr<const PeakShapeFactory>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEFACTORY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSpherical.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSpherical.h
index 1b39559df28eb984b9084bdc244be40dbb3f4a1d..4a0dda1ae2084b2e2e7ea700b36f7090f50780db 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSpherical.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSpherical.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPESPHERICAL_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPESPHERICAL_H_
+#pragma once
 
 #include "MantidDataObjects/PeakShapeBase.h"
 #include "MantidKernel/SpecialCoordinateSystem.h"
@@ -60,5 +59,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPESPHERICAL_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSphericalFactory.h b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSphericalFactory.h
index cfc0a602666db4c9d92ce502dde81ba805b85af6..c86134567f8d64e80248871e3afb1a59a68c0ecf 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSphericalFactory.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeakShapeSphericalFactory.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORY_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORY_H_
+#pragma once
 
 #include "MantidDataObjects/PeakShapeFactory.h"
 #include "MantidKernel/System.h"
@@ -35,5 +34,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PeaksWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/PeaksWorkspace.h
index 3e5cb6b1bbbd80269194cc53c976d984394a6df7..ecc9f8d0dd8bcd5c9ee6d6befc0e5eef82086d44 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PeaksWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PeaksWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSPACE_H_
-#define MANTID_DATAOBJECTS_PEAKSPACE_H_ 1
+#pragma once
 
 #include "MantidAPI/Column.h"
 #include "MantidAPI/ExperimentInfo.h"
@@ -288,5 +287,4 @@ using PeaksWorkspace_sptr = boost::shared_ptr<PeaksWorkspace>;
 /// Typedef for a shared pointer to a const peaks workspace.
 using PeaksWorkspace_const_sptr = boost::shared_ptr<const PeaksWorkspace>;
 } // namespace DataObjects
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/PrecompiledHeader.h b/Framework/DataObjects/inc/MantidDataObjects/PrecompiledHeader.h
index 59e0459fa4deb762d152e447bd07b060632e506c..14081f94966d15d6e326796df01bfd49eb5ef84b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/PrecompiledHeader.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/PrecompiledHeader.h
@@ -4,10 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PRECOMPILEDHEADER_H_
-#define MANTID_DATAOBJECTS_PRECOMPILEDHEADER_H_
+#pragma once
 
 // Mantid
 #include "MantidAPI/Algorithm.h"
-
-#endif // MANTID_DATAOBJECTS_PRECOMPILEDHEADER_H_
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/RebinnedOutput.h b/Framework/DataObjects/inc/MantidDataObjects/RebinnedOutput.h
index 4335a7c7d0fb4a6d9133415e45220b9cf625508e..ba52e57e7fc280200674b560fa4d0fbcbdcb9d18 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/RebinnedOutput.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/RebinnedOutput.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_REBINNEDOUTPUT_H_
-#define MANTID_DATAOBJECTS_REBINNEDOUTPUT_H_
+#pragma once
 
 #include "MantidAPI/ISpectrum.h"
 #include "MantidDataObjects/Workspace2D.h"
@@ -104,5 +103,3 @@ using RebinnedOutput_const_sptr = boost::shared_ptr<const RebinnedOutput>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_REBINNEDOUTPUT_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/ReflectometryTransform.h b/Framework/DataObjects/inc/MantidDataObjects/ReflectometryTransform.h
index a5061377b01852c8bc180a081a239338fb2fdc14..409b1821cb5c25f316a49605528b914047e269de 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/ReflectometryTransform.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/ReflectometryTransform.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_REFLECTOMETRYMDTRANFORM_H_
-#define MANTID_DATAOBJECTS_REFLECTOMETRYMDTRANFORM_H_
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidAPI/IEventWorkspace_fwd.h"
@@ -110,5 +109,4 @@ initAngularCaches(const Mantid::API::MatrixWorkspace *const workspace);
 // Helper typedef for scoped pointer of this type.
 using ReflectometryTransform_sptr = boost::shared_ptr<ReflectometryTransform>;
 } // namespace DataObjects
-} // namespace Mantid
-#endif
+} // namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/ScanningWorkspaceBuilder.h b/Framework/DataObjects/inc/MantidDataObjects/ScanningWorkspaceBuilder.h
index e4089a240615337059c382975ed91c2d3c040d90..84798e6ba9ce8114f18667189c8a9707068bd8f2 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/ScanningWorkspaceBuilder.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/ScanningWorkspaceBuilder.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDER_H_
-#define MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDER_H_
+#pragma once
 
 #include "MantidAPI/MatrixWorkspace.h"
 #include "MantidDataObjects/DllConfig.h"
@@ -103,5 +102,3 @@ private:
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDER_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/SkippingPolicy.h b/Framework/DataObjects/inc/MantidDataObjects/SkippingPolicy.h
index 66d2e685594bbba7fe8665ed15106c0e1a579cac..1ad13e25735ece618b7aa8e3437c4aa23334d8a5 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/SkippingPolicy.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/SkippingPolicy.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SKIPPINGPOLICY_H_
-#define MANTID_DATAOBJECTS_SKIPPINGPOLICY_H_
+#pragma once
 
 #include "MantidAPI/IMDIterator.h"
 #include "MantidDataObjects/SkippingPolicy.h"
@@ -55,5 +54,3 @@ using SkippingPolicy_scptr = boost::scoped_ptr<SkippingPolicy>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_SKIPPINGPOLICY_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/SpecialWorkspace2D.h b/Framework/DataObjects/inc/MantidDataObjects/SpecialWorkspace2D.h
index ad588a247ba165fa88b37f7cea53c22ff148dcb9..fac0d0c92594a367166b36af5b7c21d476d2ab4b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/SpecialWorkspace2D.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/SpecialWorkspace2D.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SPECIALWORKSPACE2D_H_
-#define MANTID_DATAOBJECTS_SPECIALWORKSPACE2D_H_
+#pragma once
 
 #include "MantidAPI/MatrixWorkspace_fwd.h"
 #include "MantidDataObjects/Workspace2D.h"
@@ -105,5 +104,3 @@ using SpecialWorkspace2D_const_sptr =
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_SPECIALWORKSPACE2D_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/SplittersWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/SplittersWorkspace.h
index 713508a45e681a92d66be813b537aa5d7a09c046..1c74bb83b216e5aeda7ac7e8e538303e20c5809d 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/SplittersWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/SplittersWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SPLITTERSWORKSPACE_H_
-#define MANTID_DATAOBJECTS_SPLITTERSWORKSPACE_H_
+#pragma once
 
 #include "MantidAPI/ISplittersWorkspace.h"
 #include "MantidDataObjects/TableWorkspace.h"
@@ -72,5 +71,3 @@ using SplittersWorkspace_const_sptr =
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_SPLITTERSWORKSPACE_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/TableColumn.h b/Framework/DataObjects/inc/MantidDataObjects/TableColumn.h
index 3c300d4fb1609717bde54b223c3a735bc84fc9d1..e7519ec8a726c03c94c360ae462602a57f838ba0 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/TableColumn.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/TableColumn.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_TABLECOLUMN_H_
-#define MANTID_DATAOBJECTS_TABLECOLUMN_H_
+#pragma once
 
 #include <boost/numeric/conversion/cast.hpp>
 #include <boost/shared_ptr.hpp>
@@ -583,5 +582,3 @@ public:
            .subscribe<Mantid::DataObjects::TableColumn<DataType>>(#TypeName),  \
        0));                                                                    \
   }
-
-#endif /*MANTID_DATAOBJECTS_TABLECOLUMN_H_*/
diff --git a/Framework/DataObjects/inc/MantidDataObjects/TableWorkspace.h b/Framework/DataObjects/inc/MantidDataObjects/TableWorkspace.h
index eba76645dc5c426ea8f9d39d34a5534e0d73e1b6..6b2d539b7173de101221033c0833ca2a197c9f97 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/TableWorkspace.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/TableWorkspace.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_TABLEWORKSPACE_H_
-#define MANTID_DATAOBJECTS_TABLEWORKSPACE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -420,5 +419,3 @@ using TableWorkspace_const_sptr = boost::shared_ptr<const TableWorkspace>;
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /*MANTID_DATAOBJECTS_TABLEWORKSPACE_H_*/
diff --git a/Framework/DataObjects/inc/MantidDataObjects/VectorColumn.h b/Framework/DataObjects/inc/MantidDataObjects/VectorColumn.h
index 646d144d80e2b25ef66be5578ec0e551b32d5fc4..e99dc5bc8f9854c7b7073831eef070a07e7709a5 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/VectorColumn.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/VectorColumn.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_VECTORCOLUMN_H_
-#define MANTID_DATAOBJECTS_VECTORCOLUMN_H_
+#pragma once
 
 #include "MantidAPI/Column.h"
 #include "MantidKernel/StringTokenizer.h"
@@ -210,5 +209,3 @@ private:
   Kernel::RegistrationHelper register_column_##TypeName((                      \
       API::ColumnFactory::Instance().subscribe<VectorColumn<Type>>(#TypeName), \
       0));
-
-#endif /* MANTID_DATAOBJECTS_VECTORCOLUMN_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/Workspace2D.h b/Framework/DataObjects/inc/MantidDataObjects/Workspace2D.h
index 19489f400a2db0e1f485d7ae2db23c965e386aae..2848ecb7d5e86b34cc1d6e545d30b37dd15a0a84 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/Workspace2D.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/Workspace2D.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_WORKSPACE2D_H_
-#define MANTID_DATAOBJECTS_WORKSPACE2D_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -112,5 +111,4 @@ using Workspace2D_sptr = boost::shared_ptr<Workspace2D>;
 using Workspace2D_const_sptr = boost::shared_ptr<const Workspace2D>;
 
 } // namespace DataObjects
-} // Namespace Mantid
-#endif /*MANTID_DATAOBJECTS_WORKSPACE2D_H_*/
+} // Namespace Mantid
\ No newline at end of file
diff --git a/Framework/DataObjects/inc/MantidDataObjects/WorkspaceCreation.h b/Framework/DataObjects/inc/MantidDataObjects/WorkspaceCreation.h
index daf7ccfc34da9cf810338af4d258c6d8d3e1ce08..913858c51e9f472857d481389c649f626bcf606b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/WorkspaceCreation.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/WorkspaceCreation.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_WORKSPACECREATION_H_
-#define MANTID_DATAOBJECTS_WORKSPACECREATION_H_
+#pragma once
 
 #include "MantidDataObjects/DllConfig.h"
 #include "MantidHistogramData/Histogram.h"
@@ -244,5 +243,3 @@ std::unique_ptr<T> create(const P &parent,
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /* MANTID_DATAOBJECTS_WORKSPACECREATION_H_ */
diff --git a/Framework/DataObjects/inc/MantidDataObjects/WorkspaceSingleValue.h b/Framework/DataObjects/inc/MantidDataObjects/WorkspaceSingleValue.h
index e6296ed95c954d208a1bfee1fa3520cfbeb3ea14..60d4d59ab46a0c40a887d0578421834db9e1348b 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/WorkspaceSingleValue.h
+++ b/Framework/DataObjects/inc/MantidDataObjects/WorkspaceSingleValue.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_WORKSPACESINGLEVALUE_H_
-#define MANTID_DATAOBJECTS_WORKSPACESINGLEVALUE_H_
+#pragma once
 
 //----------------------------------------------------------------------
 // Includes
@@ -92,5 +91,3 @@ using WorkspaceSingleValue_const_sptr =
 
 } // namespace DataObjects
 } // namespace Mantid
-
-#endif /*MANTID_DATAOBJECTS_WORKSPACESINGLEVALUE_H_*/
diff --git a/Framework/DataObjects/test/AffineMatrixParameterParserTest.h b/Framework/DataObjects/test/AffineMatrixParameterParserTest.h
index fc28387d56a7631b2456152ced399a87304aead1..3098a09e5f39850f6fb622b514df9db7f51aeb45 100644
--- a/Framework/DataObjects/test/AffineMatrixParameterParserTest.h
+++ b/Framework/DataObjects/test/AffineMatrixParameterParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef AFFINE_MATRIX_PARAMETER_PARSER_TEST_H
-#define AFFINE_MATRIX_PARAMETER_PARSER_TEST_H
+#pragma once
 
 #include <Poco/AutoPtr.h>
 #include <Poco/DOM/DOMParser.h>
@@ -123,5 +122,4 @@ public:
     TS_ASSERT_THROWS(parser.createParameter(pRootElem),
                      const std::runtime_error &);
   }
-};
-#endif
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/AffineMatrixParameterTest.h b/Framework/DataObjects/test/AffineMatrixParameterTest.h
index e48a7d7baf2c33ed7ba37f4b718d8725c239df12..ba7b12afc15fffaf657b5b8aeda71514b30596f0 100644
--- a/Framework/DataObjects/test/AffineMatrixParameterTest.h
+++ b/Framework/DataObjects/test/AffineMatrixParameterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef AFFINE_MATRIX_PARAMETER_TEST_H
-#define AFFINE_MATRIX_PARAMETER_TEST_H
+#pragma once
 
 #include "MantidDataObjects/AffineMatrixParameter.h"
 #include "MantidGeometry/MDGeometry/MDTypes.h"
@@ -120,5 +119,3 @@ public:
         param.toXMLString());
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/BoxControllerNeXusIOTest.h b/Framework/DataObjects/test/BoxControllerNeXusIOTest.h
index 2ef2d4099d243d4e7923068e074a27207afce4c8..3e8054a1139ace21fe98f08c6f1dad927ebea02e 100644
--- a/Framework/DataObjects/test/BoxControllerNeXusIOTest.h
+++ b/Framework/DataObjects/test/BoxControllerNeXusIOTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef BOXCONTROLLER_NEXUS_IO_TEST_H
-#define BOXCONTROLLER_NEXUS_IO_TEST_H
+#pragma once
 
 #include "MantidAPI/FileFinder.h"
 #include "MantidDataObjects/BoxControllerNeXusIO.h"
@@ -239,5 +238,4 @@ private:
   Mantid::DataObjects::BoxControllerNeXusIO *createTestBoxController() {
     return new Mantid::DataObjects::BoxControllerNeXusIO(sc.get());
   }
-};
-#endif
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/CoordTransformAffineParserTest.h b/Framework/DataObjects/test/CoordTransformAffineParserTest.h
index 5b84265f64860d3d214c66f8a0c52720ddf56804..1eb7cac325e61c9090e1a26491772b0238b6d760 100644
--- a/Framework/DataObjects/test/CoordTransformAffineParserTest.h
+++ b/Framework/DataObjects/test/CoordTransformAffineParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMPARSERTEST_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMPARSERTEST_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidDataObjects/CoordTransformAffine.h"
@@ -119,5 +118,3 @@ public:
     delete product;
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/CoordTransformAffineTest.h b/Framework/DataObjects/test/CoordTransformAffineTest.h
index 7ad5cf7c94d6e32109de63bb14b0c3e4d580b18f..53cff57e5b92c790baff3e8c6e6c0748a80da5f6 100644
--- a/Framework/DataObjects/test/CoordTransformAffineTest.h
+++ b/Framework/DataObjects/test/CoordTransformAffineTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMAFFINETEST_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMAFFINETEST_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidDataObjects/CoordTransformAffine.h"
@@ -425,5 +424,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMAFFINETEST_H_ */
diff --git a/Framework/DataObjects/test/CoordTransformAlignedTest.h b/Framework/DataObjects/test/CoordTransformAlignedTest.h
index 53d3906f55a45c79eba30e77421ec788b0be076c..e1ee2c0a2c263e2750c38e97db525cc21b5b42a9 100644
--- a/Framework/DataObjects/test/CoordTransformAlignedTest.h
+++ b/Framework/DataObjects/test/CoordTransformAlignedTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMALIGNEDTEST_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMALIGNEDTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -180,5 +179,4 @@ public:
       ct.apply(in, out);
     }
   }
-};
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMALIGNEDTEST_H_ */
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/CoordTransformDistanceParserTest.h b/Framework/DataObjects/test/CoordTransformDistanceParserTest.h
index 0f9a21bada9530ce294252a7feaa85e1f1b83f39..84ca567dbfd9d80536411095240b0470fef3d42a 100644
--- a/Framework/DataObjects/test/CoordTransformDistanceParserTest.h
+++ b/Framework/DataObjects/test/CoordTransformDistanceParserTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCEPARSERTEST_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCEPARSERTEST_H_
+#pragma once
 
 #include "MantidDataObjects/CoordTransformAffine.h"
 #include "MantidDataObjects/CoordTransformDistance.h"
@@ -111,5 +110,4 @@ public:
     TS_ASSERT_THROWS_NOTHING(product = parser.createTransform(pRootElem));
     delete product;
   }
-};
-#endif
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/CoordTransformDistanceTest.h b/Framework/DataObjects/test/CoordTransformDistanceTest.h
index c9f0e9a4834a19e3c6c862443a16591b5e1e5b68..fe5832aa94f774e3318a6df58ef1490d301b963b 100644
--- a/Framework/DataObjects/test/CoordTransformDistanceTest.h
+++ b/Framework/DataObjects/test/CoordTransformDistanceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCETEST_H_
-#define MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCETEST_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidDataObjects/CoordTransformDistance.h"
@@ -157,5 +156,3 @@ public:
     TS_ASSERT_DELTA(out, .25 * 3, 1e-5);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_COORDTRANSFORMDISTANCETEST_H_ */
diff --git a/Framework/DataObjects/test/EventListTest.h b/Framework/DataObjects/test/EventListTest.h
index dc1876fb61b09746ae992531aef33dbd13840b79..2089324e76e1efa181237ad84f2657c58744440a 100644
--- a/Framework/DataObjects/test/EventListTest.h
+++ b/Framework/DataObjects/test/EventListTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef EVENTLISTTEST_H_
-#define EVENTLISTTEST_H_ 1
+#pragma once
 
 #include "MantidAPI/FrameworkManager.h"
 #include "MantidDataObjects/EventList.h"
@@ -2988,5 +2987,3 @@ public:
     TS_ASSERT_DELTA(integ, 5e6, 1);
   }
 };
-
-#endif /// EVENTLISTTEST_H_
diff --git a/Framework/DataObjects/test/EventWorkspaceMRUTest.h b/Framework/DataObjects/test/EventWorkspaceMRUTest.h
index bc4286c52566b7be28f8f70301bae7a6bfac7fc7..82706e5152323381f2c64780f3307ef7bcacbd9c 100644
--- a/Framework/DataObjects/test/EventWorkspaceMRUTest.h
+++ b/Framework/DataObjects/test/EventWorkspaceMRUTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_EVENTWORKSPACEMRUTEST_H_
-#define MANTID_DATAOBJECTS_EVENTWORKSPACEMRUTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -23,5 +22,3 @@ public:
     TS_ASSERT_EQUALS(mru.MRUSize(), 0);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_EVENTWORKSPACEMRUTEST_H_ */
diff --git a/Framework/DataObjects/test/EventWorkspaceTest.h b/Framework/DataObjects/test/EventWorkspaceTest.h
index 02003ebef886aacb8e5d96cf8fd4478ce85cb9fd..4923ac338a39851769c915273da6dabdb290c587 100644
--- a/Framework/DataObjects/test/EventWorkspaceTest.h
+++ b/Framework/DataObjects/test/EventWorkspaceTest.h
@@ -11,8 +11,7 @@
  *      Author: Janik Zikovsky
  */
 
-#ifndef EVENTWORKSPACETEST_H_
-#define EVENTWORKSPACETEST_H_
+#pragma once
 
 #include <boost/date_time/gregorian/gregorian.hpp>
 #include <boost/date_time/posix_time/posix_time.hpp>
@@ -844,5 +843,3 @@ public:
     static_cast<void>(new (memory) EventList());
   }
 };
-
-#endif /* EVENTWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/EventsTest.h b/Framework/DataObjects/test/EventsTest.h
index 68e2625ae451b18579a13bda7fd9b602e324016b..30b5db888702354d9038f6e8a68d72621b818f56 100644
--- a/Framework/DataObjects/test/EventsTest.h
+++ b/Framework/DataObjects/test/EventsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef EVENTSTEST_H_
-#define EVENTSTEST_H_ 1
+#pragma once
 
 #include "MantidDataObjects/Events.h"
 #include <cxxtest/TestSuite.h>
@@ -59,5 +58,3 @@ public:
     TS_ASSERT(notimeEvent1.equals(notimeEvent2, .1, .1));
   }
 };
-
-#endif /// EVENTSTEST_H_
diff --git a/Framework/DataObjects/test/FakeMDTest.h b/Framework/DataObjects/test/FakeMDTest.h
index b0764fe5c817c03657cf6605e7bdc1c1a7f48a66..d35aca470affbf979cc039dca6d8442ad2d4c50a 100644
--- a/Framework/DataObjects/test/FakeMDTest.h
+++ b/Framework/DataObjects/test/FakeMDTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_FAKEMDTEST_H_
-#define MANTID_DATAOBJECTS_FAKEMDTEST_H_
+#pragma once
 
 #include <vector>
 
@@ -158,5 +157,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_FakeMD_H_ */
diff --git a/Framework/DataObjects/test/GroupingWorkspaceTest.h b/Framework/DataObjects/test/GroupingWorkspaceTest.h
index e63b8bca7b039eae15c3fb55e27d9fe0b41fc0fa..3b152c7b331610081dd5a89016d20fd198231996 100644
--- a/Framework/DataObjects/test/GroupingWorkspaceTest.h
+++ b/Framework/DataObjects/test/GroupingWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_GROUPINGWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_GROUPINGWORKSPACETEST_H_
+#pragma once
 
 #include "MantidDataObjects/GroupingWorkspace.h"
 #include "MantidKernel/System.h"
@@ -132,5 +131,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_GROUPINGWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/Histogram1DTest.h b/Framework/DataObjects/test/Histogram1DTest.h
index 8509ef2d3769eeb13f035354a3e609ec8ca0b657..5db8328f8470b2a84b5a5bdd100aac1577977631 100644
--- a/Framework/DataObjects/test/Histogram1DTest.h
+++ b/Framework/DataObjects/test/Histogram1DTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TESTHISTOGRAM1D_
-#define TESTHISTOGRAM1D_
+#pragma once
 
 #include <algorithm>
 #include <boost/shared_ptr.hpp>
@@ -277,5 +276,4 @@ public:
     TS_ASSERT_EQUALS(clone.readY()[0], 0.2);
     TS_ASSERT_EQUALS(clone.readE()[0], 0.3);
   }
-};
-#endif /*TESTHISTOGRAM1D_*/
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/MDBinTest.h b/Framework/DataObjects/test/MDBinTest.h
index 257824af7b63976e0d1b15e1b077ca58baca9e0a..357b42559726524775d978ea1dbfcca51b2e73c8 100644
--- a/Framework/DataObjects/test/MDBinTest.h
+++ b/Framework/DataObjects/test/MDBinTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBINTEST_H_
-#define MANTID_DATAOBJECTS_MDBINTEST_H_
+#pragma once
 
 #include "MantidDataObjects/MDBin.h"
 #include "MantidDataObjects/MDEventFactory.h"
@@ -27,5 +26,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDBINTEST_H_ */
diff --git a/Framework/DataObjects/test/MDBoxBaseTest.h b/Framework/DataObjects/test/MDBoxBaseTest.h
index 4515dab6b774e5bd9d38e71ee46886b03af4cd17..6b8f00416ec6d34679a747d128deac3812bfe338 100644
--- a/Framework/DataObjects/test/MDBoxBaseTest.h
+++ b/Framework/DataObjects/test/MDBoxBaseTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBOXBASETEST_H_
-#define MANTID_DATAOBJECTS_MDBOXBASETEST_H_
+#pragma once
 
 #include "MantidAPI/CoordTransform.h"
 #include "MantidDataObjects/MDBoxBase.h"
@@ -499,5 +498,3 @@ public:
     }
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDBOXBASETEST_H_ */
diff --git a/Framework/DataObjects/test/MDBoxFlatTreeTest.h b/Framework/DataObjects/test/MDBoxFlatTreeTest.h
index 3f7b600ac0ef8631ee93409eecb76a185be79de0..f80c08cb9e7e5b5959e45f8da3e9f9338751f112 100644
--- a/Framework/DataObjects/test/MDBoxFlatTreeTest.h
+++ b/Framework/DataObjects/test/MDBoxFlatTreeTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBOX_FLATTREE_H_
-#define MANTID_DATAOBJECTS_MDBOX_FLATTREE_H_
+#pragma once
 
 #include "MantidDataObjects/MDBoxFlatTree.h"
 #include "MantidDataObjects/MDLeanEvent.h"
@@ -111,5 +110,3 @@ public:
 private:
   Mantid::API::IMDEventWorkspace_sptr spEw3;
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDBoxIteratorTest.h b/Framework/DataObjects/test/MDBoxIteratorTest.h
index cd2d81ff8d44edbba5417a9f7e99720c387f37a3..19ec4fc80a6bb51685a449acbfa40172ceffb39d 100644
--- a/Framework/DataObjects/test/MDBoxIteratorTest.h
+++ b/Framework/DataObjects/test/MDBoxIteratorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDBOXITERATORTEST_H_
-#define MANTID_DATAOBJECTS_MDBOXITERATORTEST_H_
+#pragma once
 
 #include "MantidDataObjects/MDBox.h"
 #include "MantidDataObjects/MDBoxIterator.h"
@@ -773,6 +772,4 @@ public:
     do_test_getBoxes(true, 3, 125 * 125 * 125);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDBOXITERATORTEST_H_ */
 #undef RUN_CXX_PERFORMANCE_TEST_EMBEDDED
diff --git a/Framework/DataObjects/test/MDBoxSaveableTest.h b/Framework/DataObjects/test/MDBoxSaveableTest.h
index 4b54bdd84bee4f5717e2bb55cc6f99afd6d06017..927c57affb22e565b6e231bb28c044ac580c000f 100644
--- a/Framework/DataObjects/test/MDBoxSaveableTest.h
+++ b/Framework/DataObjects/test/MDBoxSaveableTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDBOX_SAVEABLE_TEST_H
-#define MDBOX_SAVEABLE_TEST_H
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidDataObjects/BoxControllerNeXusIO.h"
@@ -959,5 +958,4 @@ public:
   //    do_deleteNexusFile();
   //  }
   //
-};
-#endif
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/MDBoxTest.h b/Framework/DataObjects/test/MDBoxTest.h
index 49893a611fbacfe83d57969a4a74bbe6fb2f237f..71e0a6d9382679b00006aa585a00485731409681 100644
--- a/Framework/DataObjects/test/MDBoxTest.h
+++ b/Framework/DataObjects/test/MDBoxTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDBOXTEST_H
-#define MDBOXTEST_H
+#pragma once
 
 #include "MantidAPI/BoxController.h"
 #include "MantidDataObjects/CoordTransformDistance.h"
@@ -644,5 +643,3 @@ public:
     TS_ASSERT_EQUALS(b.getEvents().capacity(), 3);
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDDimensionStatsTest.h b/Framework/DataObjects/test/MDDimensionStatsTest.h
index 05d1e3124165feae6f961c3c4b8eff57f3ab5531..c6582c319dce0ae2a0e8640459ef9aca5c2d1ca6 100644
--- a/Framework/DataObjects/test/MDDimensionStatsTest.h
+++ b/Framework/DataObjects/test/MDDimensionStatsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDDIMENSIONSTATSTEST_H_
-#define MANTID_DATAOBJECTS_MDDIMENSIONSTATSTEST_H_
+#pragma once
 
 #include "MantidDataObjects/MDDimensionStats.h"
 
@@ -37,5 +36,3 @@ public:
     TS_ASSERT_DELTA(s.getApproxVariance(), 25.0 / 3.0, 1e-4);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDDIMENSIONSTATSTEST_H_ */
diff --git a/Framework/DataObjects/test/MDEventFactoryTest.h b/Framework/DataObjects/test/MDEventFactoryTest.h
index b1d8e18a7cc1e3e584a4ac8cf30ec27803354fb4..cbff12bec36c362db408238cdec1e88e875d515c 100644
--- a/Framework/DataObjects/test/MDEventFactoryTest.h
+++ b/Framework/DataObjects/test/MDEventFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDEVENTFACTORYTEST_H_
-#define MANTID_DATAOBJECTS_MDEVENTFACTORYTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -116,5 +115,3 @@ public:
 
   size_t test_value;
 };
-
-#endif /* MANTID_DATAOBJECTS_MDEVENTFACTORYTEST_H_ */
diff --git a/Framework/DataObjects/test/MDEventInserterTest.h b/Framework/DataObjects/test/MDEventInserterTest.h
index d0223c86829ee60a1144520c7365c862e3d16a9b..6de23833720a8885cc34c62cdcbebd3581009c99 100644
--- a/Framework/DataObjects/test/MDEventInserterTest.h
+++ b/Framework/DataObjects/test/MDEventInserterTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDEVENTINSERTERTEST_H_
-#define MANTID_DATAOBJECTS_MDEVENTINSERTERTEST_H_
+#pragma once
 
 #include "MantidAPI/AlgorithmManager.h"
 #include "MantidAPI/AnalysisDataService.h"
@@ -121,5 +120,3 @@ public:
     TS_ASSERT_EQUALS(2, ws2d->getNPoints());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDEVENTINSERTERTEST_H_ */
diff --git a/Framework/DataObjects/test/MDEventTest.h b/Framework/DataObjects/test/MDEventTest.h
index 89599374ef7b46fe4b0c76c2bd656a35b941c323..5a5578f0c17ae7cb19e05979baf94ce682a6a606 100644
--- a/Framework/DataObjects/test/MDEventTest.h
+++ b/Framework/DataObjects/test/MDEventTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDEVENTTEST_H
-#define MDEVENTTEST_H
+#pragma once
 
 #include "MantidDataObjects/MDEvent.h"
 #include "MantidKernel/MultiThreaded.h"
@@ -371,5 +370,3 @@ public:
     TS_ASSERT_THROWS_NOTHING(MDEvent<4>::dataToEvents(data, transfEvents));
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDEventWorkspaceTest.h b/Framework/DataObjects/test/MDEventWorkspaceTest.h
index 0a152faa94fa28edf7e0f11c8c6a8e83d3914117..520347e22519868d7a1fa6acfc9f3813df0e5d3d 100644
--- a/Framework/DataObjects/test/MDEventWorkspaceTest.h
+++ b/Framework/DataObjects/test/MDEventWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDEVENTWORKSPACETEST_H
-#define MDEVENTWORKSPACETEST_H
+#pragma once
 
 #include "MantidAPI/AnalysisDataService.h"
 #include "MantidAPI/BoxController.h"
@@ -865,5 +864,3 @@ public:
               << clock.elapsed() << " sec\n";
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDFramesToSpecialCoordinateSystemTest.h b/Framework/DataObjects/test/MDFramesToSpecialCoordinateSystemTest.h
index 355ecfa0a21e494148fa3c369f1c00eed0c608fa..0afede36487a91178580a4df3cecbe7e76c8e69e 100644
--- a/Framework/DataObjects/test/MDFramesToSpecialCoordinateSystemTest.h
+++ b/Framework/DataObjects/test/MDFramesToSpecialCoordinateSystemTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDFRAMESTOSPECIALCOORDINATESYTEMTEST_H_
-#define MANTID_DATAOBJECTS_MDFRAMESTOSPECIALCOORDINATESYTEMTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -201,5 +200,3 @@ public:
     TSM_ASSERT("Should not be initialized", !coordinateSystem);
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDGridBoxTest.h b/Framework/DataObjects/test/MDGridBoxTest.h
index edee42b835635c3158eb29a037036d1df6c4fd8b..5106d3369f323b7f64f4f32b9578e4d488e09861 100644
--- a/Framework/DataObjects/test/MDGridBoxTest.h
+++ b/Framework/DataObjects/test/MDGridBoxTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MDGRIDBOXTEST_H
-#define MDGRIDBOXTEST_H
+#pragma once
 
 #include "MDBoxTest.h"
 #include "MantidAPI/BoxController.h"
@@ -1780,5 +1779,3 @@ public:
     }
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/MDHistoWorkspaceIteratorTest.h b/Framework/DataObjects/test/MDHistoWorkspaceIteratorTest.h
index 8d1e7eefe1755409175621a04fc7348e849b8e5e..053551e40d1d3048d150c520d899b2ead4565a24 100644
--- a/Framework/DataObjects/test/MDHistoWorkspaceIteratorTest.h
+++ b/Framework/DataObjects/test/MDHistoWorkspaceIteratorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATORTEST_H_
-#define MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATORTEST_H_
+#pragma once
 
 #include "MantidDataObjects/MDHistoWorkspace.h"
 #include "MantidDataObjects/MDHistoWorkspaceIterator.h"
@@ -1522,5 +1521,3 @@ public:
     } while (iterator.next());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDHISTOWORKSPACEITERATORTEST_H_ */
diff --git a/Framework/DataObjects/test/MDHistoWorkspaceTest.h b/Framework/DataObjects/test/MDHistoWorkspaceTest.h
index f51d8d524774535b1f23e47b52374a01bd0f537d..1313c820e4d730f9002a13d94748c2ba4b4d2935 100644
--- a/Framework/DataObjects/test/MDHistoWorkspaceTest.h
+++ b/Framework/DataObjects/test/MDHistoWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDHISTOWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_MDHISTOWORKSPACETEST_H_
+#pragma once
 
 #include "MantidAPI/ExperimentInfo.h"
 #include "MantidAPI/IMDIterator.h"
@@ -1280,5 +1279,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDHISTOWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/MDLeanEventTest.h b/Framework/DataObjects/test/MDLeanEventTest.h
index 93c6980f87d63dd59fd70409bb771d7a6adff2de..8948c728f5dbe94cc81d78f92e934dcac673a605 100644
--- a/Framework/DataObjects/test/MDLeanEventTest.h
+++ b/Framework/DataObjects/test/MDLeanEventTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MDLEANEVENTTEST_H_
-#define MANTID_DATAOBJECTS_MDLEANEVENTTEST_H_
+#pragma once
 
 #include "MantidDataObjects/MDLeanEvent.h"
 #include "MantidDataObjects/MortonIndex/WideInt.h"
@@ -161,5 +160,3 @@ public:
     TS_ASSERT_EQUALS(event.getCenter(2), 5);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_MDLEANEVENTTEST_H_ */
diff --git a/Framework/DataObjects/test/MaskWorkspaceTest.h b/Framework/DataObjects/test/MaskWorkspaceTest.h
index 6b488faaff69161ab5f2ffdd0f8c02d07e9b5f69..ca58891e051fa1e437365676795c208000ee4e96 100644
--- a/Framework/DataObjects/test/MaskWorkspaceTest.h
+++ b/Framework/DataObjects/test/MaskWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MASKWORKSPACETEST_H
-#define MANTID_DATAOBJECTS_MASKWORKSPACETEST_H
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -152,5 +151,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif // MANTID_DATAOBJECTS_MASKWORKSPACETEST_H
diff --git a/Framework/DataObjects/test/MementoTableWorkspaceTest.h b/Framework/DataObjects/test/MementoTableWorkspaceTest.h
index 83e00015b6ee49a7fb04eb28ed5ba4d159296d33..715f72e2b8d6ed2087010b7fea9c7ae15b7e6877 100644
--- a/Framework/DataObjects/test/MementoTableWorkspaceTest.h
+++ b/Framework/DataObjects/test/MementoTableWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_MEMENTOTABLEWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_MEMENTOTABLEWORKSPACETEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -102,5 +101,3 @@ public:
                MementoTableWorkspace::isMementoWorkspace(standard));
   }
 };
-
-#endif
\ No newline at end of file
diff --git a/Framework/DataObjects/test/MockObjects.h b/Framework/DataObjects/test/MockObjects.h
index d402fad089fd183f650bac70e184733734b29e46..e375eb426dcaa5c9fce49073498eda4c400e7c87 100644
--- a/Framework/DataObjects/test/MockObjects.h
+++ b/Framework/DataObjects/test/MockObjects.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MOCKOBJECTS_H_
-#define MOCKOBJECTS_H_
+#pragma once
 
 #include "MantidDataObjects/PeakShapeFactory.h"
 #include "MantidGeometry/Crystal/PeakShape.h"
@@ -44,5 +43,3 @@ public:
 } // namespace Mantid
 
 GNU_DIAG_ON_SUGGEST_OVERRIDE
-
-#endif /* MOCKOBJECTS_H_ */
diff --git a/Framework/DataObjects/test/NoShapeTest.h b/Framework/DataObjects/test/NoShapeTest.h
index ad4be140be3e44940d466deebc9a0b377319c224..a3f58ec39842b11b23354ca0c292e61eecc3b613 100644
--- a/Framework/DataObjects/test/NoShapeTest.h
+++ b/Framework/DataObjects/test/NoShapeTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPENONETEST_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPENONETEST_H_
+#pragma once
 
 #ifdef _MSC_VER
 // 'identifier' : class 'type' needs to have dll-interface to be used by clients
@@ -64,5 +63,3 @@ public:
     TS_ASSERT_EQUALS("none", shape.shapeName());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPENONETEST_H_ */
diff --git a/Framework/DataObjects/test/OffsetsWorkspaceTest.h b/Framework/DataObjects/test/OffsetsWorkspaceTest.h
index 31f446ae909f65b616cd09c59752dbe7d270b7b1..14ed0b31f26b9efcb802a49072ec171da5a255c3 100644
--- a/Framework/DataObjects/test/OffsetsWorkspaceTest.h
+++ b/Framework/DataObjects/test/OffsetsWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_OFFSETSWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_OFFSETSWORKSPACETEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -61,5 +60,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_OFFSETSWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/PeakColumnTest.h b/Framework/DataObjects/test/PeakColumnTest.h
index 7d31089ad196bd7ff155ebb37eb661f5a5898b17..4f4f4df54e036081e69f39ce5627362bf29c1756 100644
--- a/Framework/DataObjects/test/PeakColumnTest.h
+++ b/Framework/DataObjects/test/PeakColumnTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKCOLUMNTEST_H_
-#define MANTID_DATAOBJECTS_PEAKCOLUMNTEST_H_
+#pragma once
 
 #include "MantidDataObjects/Peak.h"
 #include "MantidDataObjects/PeakColumn.h"
@@ -179,5 +178,3 @@ private:
   Mantid::Geometry::Instrument_sptr m_inst;
   std::vector<Peak> m_peaks;
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKCOLUMNTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakNoShapeFactoryTest.h b/Framework/DataObjects/test/PeakNoShapeFactoryTest.h
index f53f5bf706e27874a27663235f307cf42f2f1ef2..0e4dedfc2ffbf05a322acf480ca0a7ddbf330efa 100644
--- a/Framework/DataObjects/test/PeakNoShapeFactoryTest.h
+++ b/Framework/DataObjects/test/PeakNoShapeFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORYTEST_H_
-#define MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORYTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -31,5 +30,3 @@ public:
     delete product;
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKNOSHAPEFACTORYTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakShapeEllipsoidFactoryTest.h b/Framework/DataObjects/test/PeakShapeEllipsoidFactoryTest.h
index 31e1082fd5efd377dff507c9024bde3720a7153c..84de32e67c620203a551f6d48319f9437a5d7a68 100644
--- a/Framework/DataObjects/test/PeakShapeEllipsoidFactoryTest.h
+++ b/Framework/DataObjects/test/PeakShapeEllipsoidFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORYTEST_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORYTEST_H_
+#pragma once
 
 #ifdef _MSC_VER
 // 'identifier' : class 'type' needs to have dll-interface to be used by clients
@@ -98,5 +97,3 @@ public:
     delete productShape;
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDFACTORYTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakShapeEllipsoidTest.h b/Framework/DataObjects/test/PeakShapeEllipsoidTest.h
index ed148e15aa14d21dc6af32a058eca1f186adbe5d..9dc7153f57a45140ae2747f6ef4f7bb466a726cc 100644
--- a/Framework/DataObjects/test/PeakShapeEllipsoidTest.h
+++ b/Framework/DataObjects/test/PeakShapeEllipsoidTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDTEST_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -283,5 +282,3 @@ public:
                      delta);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPEELLIPSOIDTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakShapeSphericalFactoryTest.h b/Framework/DataObjects/test/PeakShapeSphericalFactoryTest.h
index 3c437f1be19991d346930204eb79f39693ca85ae..b19df384d81c22579de2bd907c6bc4d43b5b5a39 100644
--- a/Framework/DataObjects/test/PeakShapeSphericalFactoryTest.h
+++ b/Framework/DataObjects/test/PeakShapeSphericalFactoryTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORYTEST_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORYTEST_H_
+#pragma once
 
 #ifdef _MSC_VER
 // 'identifier' : class 'type' needs to have dll-interface to be used by clients
@@ -114,5 +113,3 @@ public:
     delete productShape;
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPESPHERICALFACTORYTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakShapeSphericalTest.h b/Framework/DataObjects/test/PeakShapeSphericalTest.h
index b28621056eaa2bfb4866403b37f72474c9175fd3..c33cfe511ea00e9be8721c3219cee2f35bca6d01 100644
--- a/Framework/DataObjects/test/PeakShapeSphericalTest.h
+++ b/Framework/DataObjects/test/PeakShapeSphericalTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSHAPESPHERICALTEST_H_
-#define MANTID_DATAOBJECTS_PEAKSHAPESPHERICALTEST_H_
+#pragma once
 
 #ifdef _MSC_VER
 // 'identifier' : class 'type' needs to have dll-interface to be used by clients
@@ -249,5 +248,3 @@ public:
     TS_ASSERT_EQUALS("spherical", shape.shapeName());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSHAPESPHERICALTEST_H_ */
diff --git a/Framework/DataObjects/test/PeakTest.h b/Framework/DataObjects/test/PeakTest.h
index 0270964ba168d7ffbbd1fee1e767ed901143799a..bd787fcac431493d6274e3dcdd67fb56cfa6b9a0 100644
--- a/Framework/DataObjects/test/PeakTest.h
+++ b/Framework/DataObjects/test/PeakTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKTEST_H_
-#define MANTID_DATAOBJECTS_PEAKTEST_H_
+#pragma once
 
 #include "MantidGeometry/Instrument/ReferenceFrame.h"
 #include "MantidKernel/PhysicalConstants.h"
@@ -629,5 +628,3 @@ private:
     }
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKTEST_H_ */
diff --git a/Framework/DataObjects/test/PeaksWorkspaceTest.h b/Framework/DataObjects/test/PeaksWorkspaceTest.h
index e2cc914e77572e69c20660610a93ba5a22c06c0b..790a466460e96406600582d47da202ef8e011d31 100644
--- a/Framework/DataObjects/test/PeaksWorkspaceTest.h
+++ b/Framework/DataObjects/test/PeaksWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_PEAKSWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_PEAKSWORKSPACETEST_H_
+#pragma once
 
 #include "MantidAPI/AlgorithmManager.h"
 #include "MantidAPI/FileProperty.h"
@@ -649,5 +648,3 @@ private:
     TS_ASSERT_EQUALS("DetectorID", column1->name());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_PEAKSWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/PrecompiledHeader.h b/Framework/DataObjects/test/PrecompiledHeader.h
index ea5dcc8f97079c9ec532364d60de0687d13634fb..32a9ee3a6db62de1130e99fdfa0b3e4b7750d172 100644
--- a/Framework/DataObjects/test/PrecompiledHeader.h
+++ b/Framework/DataObjects/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_DATAOBJECTSTEST_PRECOMPILED_HEADER_H_
-#define MANTID_DATAOBJECTSTEST_PRECOMPILED_HEADER_H_
+#pragma once
 
 // cxxtest
 #include <cxxtest/WrappedTestSuite.h>
@@ -16,5 +15,3 @@
 #include <set>
 #include <string>
 #include <vector>
-
-#endif // MANTID_DATAOBJECTSTEST_PRECOMPILED_HEADER_H_
\ No newline at end of file
diff --git a/Framework/DataObjects/test/PropertyManagerHelper.h b/Framework/DataObjects/test/PropertyManagerHelper.h
index fafc906ecfffd365d0ba329ed68ea397c00b35c8..aa228d879bed8ae442dd39a3bb475de095e573dd 100644
--- a/Framework/DataObjects/test/PropertyManagerHelper.h
+++ b/Framework/DataObjects/test/PropertyManagerHelper.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef DATAOBJECTSTEST_PROPERTYMANAGERHELPER_H_
-#define DATAOBJECTSTEST_PROPERTYMANAGERHELPER_H_
+#pragma once
 
 #include "MantidKernel/PropertyManager.h"
 
@@ -21,5 +20,3 @@ public:
   using PropertyManager::declareProperty;
   using PropertyManager::setProperty;
 };
-
-#endif
diff --git a/Framework/DataObjects/test/RebinnedOutputTest.h b/Framework/DataObjects/test/RebinnedOutputTest.h
index f299ec4d8f2537bdbef24786132dabb22625e6e1..306072243b8c705b177ed7c5259eaec89903a7c4 100644
--- a/Framework/DataObjects/test/RebinnedOutputTest.h
+++ b/Framework/DataObjects/test/RebinnedOutputTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_REBINNEDOUTPUTTEST_H_
-#define MANTID_DATAOBJECTS_REBINNEDOUTPUTTEST_H_
+#pragma once
 
 #include "MantidKernel/System.h"
 #include "MantidKernel/Timer.h"
@@ -70,5 +69,3 @@ public:
     TS_ASSERT_EQUALS(ws->dataF(1)[3], 2.);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_REBINNEDOUTPUTTEST_H_ */
diff --git a/Framework/DataObjects/test/RefAxisTest.h b/Framework/DataObjects/test/RefAxisTest.h
index bdabefe79feb5f37541b07d1313ec8aabb18d07e..8ac015971e31e16efc80d4d1e81fe5973f0479fe 100644
--- a/Framework/DataObjects/test/RefAxisTest.h
+++ b/Framework/DataObjects/test/RefAxisTest.h
@@ -8,8 +8,7 @@
 // This set of tests has been placed in DataObjects because it really needs to
 // use a real workspace
 //-------------------------------------------------------------------------------------------------
-#ifndef REFAXISTEST_H_
-#define REFAXISTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -111,5 +110,3 @@ private:
   std::unique_ptr<MatrixWorkspace> m_space, m_space2;
   std::unique_ptr<RefAxis> m_refAxis;
 };
-
-#endif /*REFAXISTEST_H_*/
diff --git a/Framework/DataObjects/test/ReflectometryTransformTest.h b/Framework/DataObjects/test/ReflectometryTransformTest.h
index 625864efee401e4458e3f2221228e2ec0d1121e5..37f2eea5d5a9cdd2f2b884fec89d87114d4157f6 100644
--- a/Framework/DataObjects/test/ReflectometryTransformTest.h
+++ b/Framework/DataObjects/test/ReflectometryTransformTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_REFLECTOMETRYTRANSFORTEST_H_
-#define MANTID_DATAOBJECTS_REFLECTOMETRYTRANSFORTEST_H_
+#pragma once
 
 #include "MantidAPI/SpectrumInfo.h"
 #include "MantidDataObjects/ReflectometryTransform.h"
@@ -99,5 +98,3 @@ public:
     TS_ASSERT_DELTA(0.06, cache.detectorHeights[0], 1e6);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_REFLECTOMETRYTRANSFORTEST_H_ */
diff --git a/Framework/DataObjects/test/ScanningWorkspaceBuilderTest.h b/Framework/DataObjects/test/ScanningWorkspaceBuilderTest.h
index e7b55d9ebf18c6bffd3918f40e83f8da7ce23a3e..333a6846a7acb6414a188740b988eead551100d0 100644
--- a/Framework/DataObjects/test/ScanningWorkspaceBuilderTest.h
+++ b/Framework/DataObjects/test/ScanningWorkspaceBuilderTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDERTEST_H_
-#define MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDERTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -631,5 +630,3 @@ public:
     ws = builder.buildWorkspace();
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_SCANNINGWORKSPACEBUILDERTEST_H_ */
diff --git a/Framework/DataObjects/test/SkippingPolicyTest.h b/Framework/DataObjects/test/SkippingPolicyTest.h
index 1839c894444be3ef069ba0f3b8eb77fe7583c718..a6c9bb899e1196dd786d92ab7f650ba940619df4 100644
--- a/Framework/DataObjects/test/SkippingPolicyTest.h
+++ b/Framework/DataObjects/test/SkippingPolicyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SKIPPINGPOLICYTEST_H_
-#define MANTID_DATAOBJECTS_SKIPPINGPOLICYTEST_H_
+#pragma once
 
 #include "MantidDataObjects/SkippingPolicy.h"
 #include <cxxtest/TestSuite.h>
@@ -25,5 +24,3 @@ public:
     TSM_ASSERT_EQUALS("Should alway return False", false, p.keepGoing());
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_SKIPPINGPOLICYTEST_H_ */
diff --git a/Framework/DataObjects/test/SpecialWorkspace2DTest.h b/Framework/DataObjects/test/SpecialWorkspace2DTest.h
index 9ae01f62435ebc740d2c09844269a43879c29946..980577ca338ad8af05c9b736c27bfb4811598948 100644
--- a/Framework/DataObjects/test/SpecialWorkspace2DTest.h
+++ b/Framework/DataObjects/test/SpecialWorkspace2DTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SPECIALWORKSPACE2DTEST_H_
-#define MANTID_DATAOBJECTS_SPECIALWORKSPACE2DTEST_H_
+#pragma once
 
 #include "MantidAPI/WorkspaceProperty.h"
 #include "MantidDataObjects/SpecialWorkspace2D.h"
@@ -254,5 +253,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_SPECIALWORKSPACE2DTEST_H_ */
diff --git a/Framework/DataObjects/test/SplittersWorkspaceTest.h b/Framework/DataObjects/test/SplittersWorkspaceTest.h
index 88801cf541f0a80eeedd18f8901772b5ebc090c1..16216b80e86565b75abaa3675736f970ea10fe86 100644
--- a/Framework/DataObjects/test/SplittersWorkspaceTest.h
+++ b/Framework/DataObjects/test/SplittersWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_SPLITTERSWORKSPACETEST_H_
-#define MANTID_DATAOBJECTS_SPLITTERSWORKSPACETEST_H_
+#pragma once
 
 #include "MantidAPI/WorkspaceProperty.h"
 #include "MantidDataObjects/SplittersWorkspace.h"
@@ -132,5 +131,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_SPLITTERSWORKSPACETEST_H_ */
diff --git a/Framework/DataObjects/test/TableColumnTest.h b/Framework/DataObjects/test/TableColumnTest.h
index 685b0c5686ecae321ca39765df9d6bee561ef5b1..74b1ac7dc50040f0bd7559189a705810834db70f 100644
--- a/Framework/DataObjects/test/TableColumnTest.h
+++ b/Framework/DataObjects/test/TableColumnTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_TABLECOLUMNTEST_H_
-#define MANTID_DATAOBJECTS_TABLECOLUMNTEST_H_
+#pragma once
 
 #include "MantidDataObjects/TableColumn.h"
 #include "MantidDataObjects/TableWorkspace.h"
@@ -522,5 +521,3 @@ private:
     return vec;
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_TABLECOLUMNTEST_H_ */
diff --git a/Framework/DataObjects/test/TableWorkspacePropertyTest.h b/Framework/DataObjects/test/TableWorkspacePropertyTest.h
index 7ae3fb7603923cf44be9d8cd10f2d5329ba3cd86..86677bcf397b33d7eb9f9617dffef76b33b1cc18 100644
--- a/Framework/DataObjects/test/TableWorkspacePropertyTest.h
+++ b/Framework/DataObjects/test/TableWorkspacePropertyTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TESTTABLEWORKSPACEPROPERTY_
-#define TESTTABLEWORKSPACEPROPERTY_
+#pragma once
 
 #include <algorithm>
 #include <boost/shared_ptr.hpp>
@@ -104,5 +103,4 @@ public:
 
 private:
   boost::shared_ptr<TableWorkspace> t;
-};
-#endif /*TESTTABLEWORKSPACE_*/
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/TableWorkspaceTest.h b/Framework/DataObjects/test/TableWorkspaceTest.h
index a96cbe477ee2dd847101ca671e8e9b81fab4f793..baa63d6f1bb18dead895bc1a5bf06b61a3ad9e05 100644
--- a/Framework/DataObjects/test/TableWorkspaceTest.h
+++ b/Framework/DataObjects/test/TableWorkspaceTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TESTTABLEWORKSPACE_
-#define TESTTABLEWORKSPACE_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -749,5 +748,3 @@ public:
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
 };
-
-#endif /*TESTTABLEWORKSPACE_*/
diff --git a/Framework/DataObjects/test/VectorColumnTest.h b/Framework/DataObjects/test/VectorColumnTest.h
index 53e4b3754abebf0462cd14e3a2e52453ff834875..027abada484481e960e44a14b44c3f728e5c316c 100644
--- a/Framework/DataObjects/test/VectorColumnTest.h
+++ b/Framework/DataObjects/test/VectorColumnTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_VECTORCOLUMNTEST_H_
-#define MANTID_DATAOBJECTS_VECTORCOLUMNTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -201,5 +200,3 @@ public:
     TS_ASSERT(col2.equalsRelErr(*compare, 1));
   }
 };
-
-#endif /* MANTID_DATAOBJECTS_VECTORCOLUMNTEST_H_ */
diff --git a/Framework/DataObjects/test/WeightedEventNoTimeTest.h b/Framework/DataObjects/test/WeightedEventNoTimeTest.h
index 2d078b9cdcca0454a7a7a91f25edc7651da33c2b..a3ed0554ab3148762577ce37765491c12c0b8d9d 100644
--- a/Framework/DataObjects/test/WeightedEventNoTimeTest.h
+++ b/Framework/DataObjects/test/WeightedEventNoTimeTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef WEIGHTEDEVENTNOTIMETEST_H_
-#define WEIGHTEDEVENTNOTIMETEST_H_ 1
+#pragma once
 
 #include "MantidDataObjects/Events.h"
 #include "MantidKernel/Timer.h"
@@ -83,5 +82,3 @@ public:
     TS_ASSERT(wen == wen2);
   }
 };
-
-#endif /// EVENTLISTTEST_H_
diff --git a/Framework/DataObjects/test/WeightedEventTest.h b/Framework/DataObjects/test/WeightedEventTest.h
index c693408862d08c2f2598c5e4a4cea0fd20b92cfc..c64ca08590c2801f7b230c952d41bda3ee7df26e 100644
--- a/Framework/DataObjects/test/WeightedEventTest.h
+++ b/Framework/DataObjects/test/WeightedEventTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef WEIGHTEDEVENTTEST_H_
-#define WEIGHTEDEVENTTEST_H_ 1
+#pragma once
 
 #include "MantidDataObjects/Events.h"
 #include "MantidKernel/Timer.h"
@@ -70,5 +69,3 @@ public:
     TS_ASSERT_EQUALS(we.error(), 1.5);
   }
 };
-
-#endif /// EVENTLISTTEST_H_
diff --git a/Framework/DataObjects/test/Workspace2DTest.h b/Framework/DataObjects/test/Workspace2DTest.h
index 641c409661fbab5744afaec442fd6bc794f1d6f0..bf6738e1a582948241f7767de7867206a86602dc 100644
--- a/Framework/DataObjects/test/Workspace2DTest.h
+++ b/Framework/DataObjects/test/Workspace2DTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef WORKSPACE2DTEST_H_
-#define WORKSPACE2DTEST_H_
+#pragma once
 
 #include "MantidAPI/ISpectrum.h"
 #include "MantidAPI/MatrixWorkspace.h"
@@ -329,5 +328,3 @@ public:
               << " spectra, using the ISpectrum method (in parallel).\n";
   }
 };
-
-#endif
diff --git a/Framework/DataObjects/test/WorkspaceCreationTest.h b/Framework/DataObjects/test/WorkspaceCreationTest.h
index 8b897eee1348a45ec4d21b5939aad9ea6e357e88..d26e0a4aa134e6fcb83f4df2a69139d294462afc 100644
--- a/Framework/DataObjects/test/WorkspaceCreationTest.h
+++ b/Framework/DataObjects/test/WorkspaceCreationTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef MANTID_DATAOBJECTS_WORKSPACECREATIONTEST_H_
-#define MANTID_DATAOBJECTS_WORKSPACECREATIONTEST_H_
+#pragma once
 
 #include <cxxtest/TestSuite.h>
 
@@ -548,5 +547,3 @@ public:
 private:
   boost::shared_ptr<Geometry::Instrument> m_instrument;
 };
-
-#endif /* MANTID_DATAOBJECTS_WORKSPACECREATIONTEST_H_ */
diff --git a/Framework/DataObjects/test/WorkspaceIteratorTest.h b/Framework/DataObjects/test/WorkspaceIteratorTest.h
index 5e065da91af21ec836cf3bdf1a1027bc69fcedc3..853ab1412efa4c5438ed3fefbb52357db30e3de1 100644
--- a/Framework/DataObjects/test/WorkspaceIteratorTest.h
+++ b/Framework/DataObjects/test/WorkspaceIteratorTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TRIPLEITERATORTEST_
-#define TRIPLEITERATORTEST_
+#pragma once
 
 #include <algorithm>
 #include <boost/shared_ptr.hpp>
@@ -175,5 +174,4 @@ public:
       TS_ASSERT_EQUALS(count, size * histogramCount * loopCount);
     }
   }
-};
-#endif /*TRIPLEITERATORTEST_*/
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/WorkspaceSingleValueTest.h b/Framework/DataObjects/test/WorkspaceSingleValueTest.h
index 5987d006df777f4d4a793f928d5400c25f9e5e7d..3071749f34658fc408c5b1a0a50d724b22af9bff 100644
--- a/Framework/DataObjects/test/WorkspaceSingleValueTest.h
+++ b/Framework/DataObjects/test/WorkspaceSingleValueTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef TESTWORKSPACESINGLEVALUE_
-#define TESTWORKSPACESINGLEVALUE_
+#pragma once
 
 #include <algorithm>
 #include <boost/shared_ptr.hpp>
@@ -101,5 +100,4 @@ public:
     TS_ASSERT(wsCastNonConst != nullptr);
     TS_ASSERT_EQUALS(wsCastConst, wsCastNonConst);
   }
-};
-#endif /*TESTWORKSPACESINGLEVALUE_*/
+};
\ No newline at end of file
diff --git a/Framework/DataObjects/test/WorkspaceValidatorsTest.h b/Framework/DataObjects/test/WorkspaceValidatorsTest.h
index 174f5234acf803fb6a3c451b48fd91fe5e456aba..77c4130ffc2e9746b499844cba63189e96f5ad13 100644
--- a/Framework/DataObjects/test/WorkspaceValidatorsTest.h
+++ b/Framework/DataObjects/test/WorkspaceValidatorsTest.h
@@ -4,8 +4,7 @@
 //     NScD Oak Ridge National Laboratory, European Spallation Source
 //     & Institut Laue - Langevin
 // SPDX - License - Identifier: GPL - 3.0 +
-#ifndef WORKSPACEVALIDATORSTEST_H_
-#define WORKSPACEVALIDATORSTEST_H_
+#pragma once
 
 #include "MantidAPI/Axis.h"
 #include "MantidAPI/CommonBinsValidator.h"
@@ -287,5 +286,3 @@ public:
     }
   }
 };
-
-#endif /*WORKSPACEVALIDATORSTEST_H_*/