diff --git a/Framework/API/inc/MantidAPI/Expression.h b/Framework/API/inc/MantidAPI/Expression.h
index d547ee5f9a3985dc8596057f18125e3f9ddda505..1452f9f4caa088946deaa548a967df4b6e61964d 100644
--- a/Framework/API/inc/MantidAPI/Expression.h
+++ b/Framework/API/inc/MantidAPI/Expression.h
@@ -75,7 +75,7 @@ public:
   /// string but recreates it.
   std::string str() const;
   /// Returns true if the expression is a function (i.e. has arguments)
-  bool isFunct() const { return m_terms.size() > 0; }
+  bool isFunct() const { return !m_terms.empty(); }
   /// Returns the name of the expression which is a function or variable name.
   std::string name() const { return m_funct; }
   /// Returns the the expression's binary operator on its left. Can be an empty
diff --git a/Framework/API/src/CompositeFunction.cpp b/Framework/API/src/CompositeFunction.cpp
index 27e8d0fd4b3f6e17dd9759c695ef275a2b0224b1..fb3bd5804ee1c0150612305972b3f811b3dc4bf5 100644
--- a/Framework/API/src/CompositeFunction.cpp
+++ b/Framework/API/src/CompositeFunction.cpp
@@ -383,7 +383,7 @@ size_t CompositeFunction::addFunction(IFunction_sptr f) {
   m_IFunction.insert(m_IFunction.end(), f->nParams(), m_functions.size());
   m_functions.push_back(f);
   //?f->init();
-  if (m_paramOffsets.size() == 0) {
+  if (m_paramOffsets.empty()) {
     m_paramOffsets.push_back(0);
     m_nParams = f->nParams();
   } else {
diff --git a/Framework/API/src/Expression.cpp b/Framework/API/src/Expression.cpp
index ec8ba7247905b98852c8cd68caa01b1f7ad6f9ff..8f3564fde4e93dc29190707ca58c71d439160f0a 100644
--- a/Framework/API/src/Expression.cpp
+++ b/Framework/API/src/Expression.cpp
@@ -134,7 +134,7 @@ void Expression::parse(const std::string &str) {
 
   tokenize();
 
-  if (m_tokens.size() == 0) {
+  if (m_tokens.empty()) {
     setFunct(m_expr);
     return;
   }
@@ -310,7 +310,7 @@ void Expression::tokenize() {
 
   } // for i
 
-  if (tokens.size()) {
+  if (!tokens.empty()) {
     // remove operators of higher prec
     m_tokens.push_back(Token(tokens[0]));
     for (size_t i = 0; i < tokens.size(); i++) {
@@ -328,7 +328,7 @@ void Expression::tokenize() {
 }
 
 std::string Expression::GetToken(size_t i) {
-  if (m_tokens.size() == 0)
+  if (m_tokens.empty())
     return m_expr;
 
   if (i < m_tokens.size()) {
@@ -345,7 +345,7 @@ std::string Expression::GetToken(size_t i) {
 }
 
 std::string Expression::GetOp(size_t i) {
-  if (m_tokens.size() == 0 || i >= m_tokens.size())
+  if (m_tokens.empty() || i >= m_tokens.size())
     return "";
 
   Token &tok = m_tokens[i];
@@ -354,7 +354,7 @@ std::string Expression::GetOp(size_t i) {
 
 void Expression::logPrint(const std::string &pads) const {
   std::string myPads = pads + "   ";
-  if (m_terms.size()) {
+  if (!m_terms.empty()) {
     std::cerr << myPads << m_op << '[' << m_funct << ']' << "(" << '\n';
     for (const auto &term : m_terms)
       term.logPrint(myPads);
@@ -442,7 +442,7 @@ std::string Expression::str() const {
     brackets = true;
   }
 
-  if (m_terms.size()) {
+  if (!m_terms.empty()) {
     if (brackets)
       res << '(';
     for (const auto &term : m_terms) {
diff --git a/Framework/API/src/FileFinder.cpp b/Framework/API/src/FileFinder.cpp
index c0f449adb2ea615a54195a9734164a28c0a7d544..84c7facade5ba818e6362c83a143f333cdea00ad 100644
--- a/Framework/API/src/FileFinder.cpp
+++ b/Framework/API/src/FileFinder.cpp
@@ -760,7 +760,7 @@ FileFinderImpl::getPath(const std::vector<IArchiveSearch_sptr> &archs,
   }
 
   // Search the archive
-  if (archs.size() != 0) {
+  if (!archs.empty()) {
     g_log.debug() << "Search the archives\n";
     std::string path = getArchivePath(archs, filenames, exts);
     try {
diff --git a/Framework/API/src/FileProperty.cpp b/Framework/API/src/FileProperty.cpp
index f151c90941820779f97ce5491ed0a8b716fdfc3f..becae0781d35b6090b06746bf2f9b186d024df14 100644
--- a/Framework/API/src/FileProperty.cpp
+++ b/Framework/API/src/FileProperty.cpp
@@ -78,7 +78,7 @@ FileProperty::FileProperty(const std::string &name,
                            unsigned int direction)
     : PropertyWithValue<std::string>(name, defaultValue,
                                      createValidator(action, exts), direction),
-      m_action(action), m_defaultExt((exts.size() > 0) ? exts.front() : ""),
+      m_action(action), m_defaultExt((!exts.empty()) ? exts.front() : ""),
       m_runFileProp(isLoadProperty() && extsMatchRunFiles()),
       m_oldLoadPropValue(""), m_oldLoadFoundFile("") {}
 
diff --git a/Framework/API/src/GridDomain.cpp b/Framework/API/src/GridDomain.cpp
index c500deb3e9b245b985c50bbff3ca706c478c1797..997c78444f6e7db54bf75c698305007ed4dc3059 100644
--- a/Framework/API/src/GridDomain.cpp
+++ b/Framework/API/src/GridDomain.cpp
@@ -16,7 +16,7 @@ Kernel::Logger g_log("GridDomain");
 
 /// number of points in the grid
 size_t GridDomain::size() const {
-  if (!m_grids.size())
+  if (m_grids.empty())
     return 0;
   else
     return std::accumulate(
diff --git a/Framework/API/src/HistoryView.cpp b/Framework/API/src/HistoryView.cpp
index a65e221f6aef8c1b568f4d178f70959675eaeca3..b7a194c3032411baef2570e07c5596a6add26565 100644
--- a/Framework/API/src/HistoryView.cpp
+++ b/Framework/API/src/HistoryView.cpp
@@ -59,7 +59,7 @@ void HistoryView::unroll(std::vector<HistoryItem>::iterator &it) {
   const auto history = it->getAlgorithmHistory();
   const auto childHistories = history->getChildHistories();
 
-  if (!it->isUnrolled() && childHistories.size() > 0) {
+  if (!it->isUnrolled() && !childHistories.empty()) {
     // mark this record as being ignored by the script builder
     it->unrolled(true);
 
diff --git a/Framework/API/src/IFunction.cpp b/Framework/API/src/IFunction.cpp
index cdbceb9cc80cb238767b7199ac78e472201da083..f0d7f8e1cdc0e3a9c64d5b8e453416aaa6a66807 100644
--- a/Framework/API/src/IFunction.cpp
+++ b/Framework/API/src/IFunction.cpp
@@ -328,7 +328,7 @@ protected:
   /// Apply if vector
   std::string apply(const std::vector<double> &v) const override {
     std::string res = "(";
-    if (v.size() > 0) {
+    if (!v.empty()) {
       for (size_t i = 0; i < v.size() - 1; ++i) {
         res += boost::lexical_cast<std::string>(v[i]) + ",";
       }
diff --git a/Framework/API/src/ISpectrum.cpp b/Framework/API/src/ISpectrum.cpp
index 60cea66c7430679436e15d7f5276168e2bf74b39..8611bb9f0b00f258e2abe8b6d3c34f814aeb87f4 100644
--- a/Framework/API/src/ISpectrum.cpp
+++ b/Framework/API/src/ISpectrum.cpp
@@ -128,7 +128,7 @@ void ISpectrum::addDetectorID(const detid_t detID) {
  * @param detIDs :: set of detector IDs to insert in set.
  */
 void ISpectrum::addDetectorIDs(const std::set<detid_t> &detIDs) {
-  if (detIDs.size() == 0)
+  if (detIDs.empty())
     return;
   this->detectorIDs.insert(detIDs.begin(), detIDs.end());
 }
@@ -138,7 +138,7 @@ void ISpectrum::addDetectorIDs(const std::set<detid_t> &detIDs) {
  * @param detIDs :: vector of detector IDs to insert in set.
  */
 void ISpectrum::addDetectorIDs(const std::vector<detid_t> &detIDs) {
-  if (detIDs.size() == 0)
+  if (detIDs.empty())
     return;
   this->detectorIDs.insert(detIDs.begin(), detIDs.end());
 }
diff --git a/Framework/API/src/MatrixWorkspace.cpp b/Framework/API/src/MatrixWorkspace.cpp
index b2049f54117eaad597f248577311a32e89c1a6ed..9d084f23591c309bc18137bf975c4970b5f8263a 100644
--- a/Framework/API/src/MatrixWorkspace.cpp
+++ b/Framework/API/src/MatrixWorkspace.cpp
@@ -707,7 +707,7 @@ void MatrixWorkspace::getIntegratedSpectra(std::vector<double> &out,
     const Mantid::MantidVec &x = this->readX(wksp_index);
     const Mantid::MantidVec &y = this->readY(wksp_index);
     // If it is a 1D workspace, no need to integrate
-    if ((x.size() <= 2) && (y.size() >= 1)) {
+    if ((x.size() <= 2) && (!y.empty())) {
       out[wksp_index] = y[0];
     } else {
       // Iterators for limits - whole range by default
diff --git a/Framework/API/src/MultiDomainFunction.cpp b/Framework/API/src/MultiDomainFunction.cpp
index e8a343ca1686c5d69e8bff7a0902e229df1a9b13..15afb0e0ab7b5fa07e426ea93ef29a99c91b8575 100644
--- a/Framework/API/src/MultiDomainFunction.cpp
+++ b/Framework/API/src/MultiDomainFunction.cpp
@@ -45,7 +45,7 @@ void MultiDomainFunction::setDomainIndices(
 void MultiDomainFunction::countNumberOfDomains() {
   std::set<size_t> dSet;
   for (auto &domain : m_domains) {
-    if (domain.second.size()) {
+    if (!domain.second.empty()) {
       dSet.insert(domain.second.begin(), domain.second.end());
     }
   }
diff --git a/Framework/API/src/MultiPeriodGroupAlgorithm.cpp b/Framework/API/src/MultiPeriodGroupAlgorithm.cpp
index 8ca6cc170638c5b861dcce618986c5e9023c54fd..ededeac2a6104b5028449c11d2015e78ebde29f1 100644
--- a/Framework/API/src/MultiPeriodGroupAlgorithm.cpp
+++ b/Framework/API/src/MultiPeriodGroupAlgorithm.cpp
@@ -35,7 +35,7 @@ bool MultiPeriodGroupAlgorithm::checkGroups() {
     m_worker.reset(new MultiPeriodGroupWorker(propName));
   }
   m_multiPeriodGroups = m_worker->findMultiPeriodGroups(this);
-  bool useDefaultGroupingBehaviour = m_multiPeriodGroups.size() == 0;
+  bool useDefaultGroupingBehaviour = m_multiPeriodGroups.empty();
   /*
    * Give the opportunity to treat this as a regular group workspace.
    */
diff --git a/Framework/API/src/MultiPeriodGroupWorker.cpp b/Framework/API/src/MultiPeriodGroupWorker.cpp
index faf3100ca97abad3601361e87b2146859a02c73d..2c9b14b33dad0b7b527bdf11583d39b05e57125f 100644
--- a/Framework/API/src/MultiPeriodGroupWorker.cpp
+++ b/Framework/API/src/MultiPeriodGroupWorker.cpp
@@ -193,7 +193,7 @@ bool MultiPeriodGroupWorker::processGroups(
     Algorithm *const sourceAlg,
     const VecWSGroupType &vecMultiPeriodGroups) const {
   // If we are not processing multiperiod groups, use the base behaviour.
-  if (vecMultiPeriodGroups.size() < 1) {
+  if (vecMultiPeriodGroups.empty()) {
     return false; // Indicates that this is not a multiperiod group workspace.
   }
   Property *outputWorkspaceProperty = sourceAlg->getProperty("OutputWorkspace");
diff --git a/Framework/API/src/MultipleFileProperty.cpp b/Framework/API/src/MultipleFileProperty.cpp
index c4bbb342cfa3c6ab4ed790d6fd70b8a3220f2822..6cf79b583aaeb58b412c0e192bc2803dedf72892 100644
--- a/Framework/API/src/MultipleFileProperty.cpp
+++ b/Framework/API/src/MultipleFileProperty.cpp
@@ -262,7 +262,7 @@ MultipleFileProperty::setValueAsMultipleFiles(const std::string &propValue) {
       // load a single (and possibly existing) file within a token, but which
       // has unexpected zero
       // padding, or some other anomaly.
-      if (flattenFileNames(f).size() == 0)
+      if (flattenFileNames(f).empty())
         f.push_back(std::vector<std::string>(1, *plusTokenString));
 
       if (plusTokenStrings.size() > 1) {
diff --git a/Framework/API/src/ParameterTie.cpp b/Framework/API/src/ParameterTie.cpp
index af5326381517bcd6474e89f8611de39a9d8114b2..b88ffb79c1a91e7ea1826280409256ea7ad7f43b 100644
--- a/Framework/API/src/ParameterTie.cpp
+++ b/Framework/API/src/ParameterTie.cpp
@@ -65,7 +65,7 @@ void ParameterTie::set(const std::string &expr) {
        it != m_varMap.end(); ++it) {
     delete it->first;
   }
-  if (m_varMap.size()) {
+  if (!m_varMap.empty()) {
     m_varMap.clear();
   }
   try { // Set the expression and initialize the variables
@@ -137,7 +137,7 @@ std::string ParameterTie::asString(const IFunction *fun) const {
   try {
     res_expression = fun->parameterName(fun->getParameterIndex(*this)) + "=";
 
-    if (m_varMap.size() == 0) { // constants
+    if (m_varMap.empty()) { // constants
       return res_expression + m_expression;
       ;
     }
diff --git a/Framework/API/src/TableRow.cpp b/Framework/API/src/TableRow.cpp
index 52b9a9438fd8642329226df01527423ec1cd785e..e75dfdac2f1b27a0cb9455726eb1a9a28118ea4a 100644
--- a/Framework/API/src/TableRow.cpp
+++ b/Framework/API/src/TableRow.cpp
@@ -11,7 +11,7 @@ TableRow::TableRow(const TableRowHelper &trh)
     : m_row(trh.m_row), m_col(0), m_sep(",") {
   for (size_t i = 0; i < trh.m_workspace->columnCount(); i++)
     m_columns.push_back(trh.m_workspace->getColumn(i));
-  if (m_columns.size())
+  if (!m_columns.empty())
     m_nrows = int(m_columns[0]->size());
   else
     m_nrows = 0;
@@ -69,7 +69,7 @@ const TableRow &TableRow::operator>>(bool &t) const {
      @return stream representation of row
  */
 std::ostream &operator<<(std::ostream &s, const TableRow &row) {
-  if (row.m_columns.size() == 0)
+  if (row.m_columns.empty())
     return s;
   if (row.m_columns.size() == 1) {
     row.m_columns[0]->print(row.row(), s);
diff --git a/Framework/API/src/WorkspaceGroup.cpp b/Framework/API/src/WorkspaceGroup.cpp
index 60daf6e06c7068b5388546a785ddec59c457e2e7..86d7afd2c04abd35a4a9dbfc3b5a26a4fa816c9a 100644
--- a/Framework/API/src/WorkspaceGroup.cpp
+++ b/Framework/API/src/WorkspaceGroup.cpp
@@ -328,7 +328,7 @@ Determine in the WorkspaceGroup is multiperiod.
 */
 bool WorkspaceGroup::isMultiperiod() const {
   std::lock_guard<std::recursive_mutex> _lock(m_mutex);
-  if (m_workspaces.size() < 1) {
+  if (m_workspaces.empty()) {
     g_log.debug("Not a multiperiod-group with < 1 nested workspace.");
     return false;
   }
diff --git a/Framework/Algorithms/src/AsymmetryCalc.cpp b/Framework/Algorithms/src/AsymmetryCalc.cpp
index 3e164376285467a08af3c5ad1c4a544e49b0d99f..86728b1d34a7907ca3f503d4705ae91a4431abf5 100644
--- a/Framework/Algorithms/src/AsymmetryCalc.cpp
+++ b/Framework/Algorithms/src/AsymmetryCalc.cpp
@@ -73,8 +73,8 @@ std::map<std::string, std::string> AsymmetryCalc::validateInputs() {
 void AsymmetryCalc::exec() {
   std::vector<int> forward_list = getProperty("ForwardSpectra");
   std::vector<int> backward_list = getProperty("BackwardSpectra");
-  int forward = forward_list.size() ? forward_list[0] : 1;
-  int backward = backward_list.size() ? backward_list[0] : 2;
+  int forward = !forward_list.empty() ? forward_list[0] : 1;
+  int backward = !backward_list.empty() ? backward_list[0] : 2;
   double alpha = getProperty("Alpha");
 
   // Get original workspace
diff --git a/Framework/Algorithms/src/CalculateFlatBackground.cpp b/Framework/Algorithms/src/CalculateFlatBackground.cpp
index efbddf393e7a9e4e2ade076b0a61de133d0bc767..72dfbb41d19fdecc51ecd7deac6f6ab8c628a631 100644
--- a/Framework/Algorithms/src/CalculateFlatBackground.cpp
+++ b/Framework/Algorithms/src/CalculateFlatBackground.cpp
@@ -311,7 +311,7 @@ void CalculateFlatBackground::checkRange(double &startX, double &endX) {
 */
 void CalculateFlatBackground::getSpecInds(std::vector<int> &output,
                                           const int workspaceTotal) {
-  if (output.size() > 0) {
+  if (!output.empty()) {
     return;
   }
 
diff --git a/Framework/Algorithms/src/CalculateResolution.cpp b/Framework/Algorithms/src/CalculateResolution.cpp
index 33894c9409d3f3011d035fb78a08499e9fedb434..c68d0746e7a55a0c1f9a5fe2ed03128f8b6f982a 100644
--- a/Framework/Algorithms/src/CalculateResolution.cpp
+++ b/Framework/Algorithms/src/CalculateResolution.cpp
@@ -127,12 +127,12 @@ void CalculateResolution::exec() {
   std::vector<double> slit1VGParam = slit1->getNumberParameter(vGapParam);
   std::vector<double> slit2VGParam = slit2->getNumberParameter(vGapParam);
 
-  if (slit1VGParam.size() < 1)
+  if (slit1VGParam.empty())
     throw std::runtime_error("Could not find a value for the first slit's "
                              "vertical gap with given parameter name: '" +
                              vGapParam + "'.");
 
-  if (slit2VGParam.size() < 1)
+  if (slit2VGParam.empty())
     throw std::runtime_error("Could not find a value for the second slit's "
                              "vertical gap with given parameter name: '" +
                              vGapParam + "'.");
diff --git a/Framework/Algorithms/src/ConvertEmptyToTof.cpp b/Framework/Algorithms/src/ConvertEmptyToTof.cpp
index 2eaeffc61bf590706d506ba5dcc42a826388d77c..ebb030ae73777b3a5518b60b58bd34727fcac8bd 100644
--- a/Framework/Algorithms/src/ConvertEmptyToTof.cpp
+++ b/Framework/Algorithms/src/ConvertEmptyToTof.cpp
@@ -165,7 +165,7 @@ void ConvertEmptyToTof::exec() {
  */
 void ConvertEmptyToTof::validateSpectraIndices(std::vector<int> &v) {
   auto nHist = m_inputWS->getNumberHistograms();
-  if (v.size() == 0) {
+  if (v.empty()) {
     g_log.information("No spectrum index given. Using all spectra to calculate "
                       "the elastic peak.");
     // use all spectra indices
@@ -190,7 +190,7 @@ void ConvertEmptyToTof::validateSpectraIndices(std::vector<int> &v) {
  */
 void ConvertEmptyToTof::validateChannelIndices(std::vector<int> &v) {
   auto blockSize = m_inputWS->blocksize() + 1;
-  if (v.size() == 0) {
+  if (v.empty()) {
     g_log.information("No channel index given. Using all channels (full "
                       "spectrum!) to calculate the elastic peak.");
     // use all channel indices
diff --git a/Framework/Algorithms/src/ConvertUnits.cpp b/Framework/Algorithms/src/ConvertUnits.cpp
index 35aacaaeeb4915c04c25412d2b338cd4e335102f..c065e40172e6884d4ca5a52a197b35ef32493285 100644
--- a/Framework/Algorithms/src/ConvertUnits.cpp
+++ b/Framework/Algorithms/src/ConvertUnits.cpp
@@ -149,7 +149,7 @@ void ConvertUnits::exec() {
 
   // If the units conversion has flipped the ascending direction of X, reverse
   // all the vectors
-  if (outputWS->dataX(0).size() &&
+  if (!outputWS->dataX(0).empty() &&
       (outputWS->dataX(0).front() > outputWS->dataX(0).back() ||
        outputWS->dataX(m_numberOfSpectra / 2).front() >
            outputWS->dataX(m_numberOfSpectra / 2).back())) {
diff --git a/Framework/Algorithms/src/ConvertUnitsUsingDetectorTable.cpp b/Framework/Algorithms/src/ConvertUnitsUsingDetectorTable.cpp
index 1d95c33d4abd0c6c0365a2063fc28984c35bcc0e..9e2d4fc2b8a20d509b58d8eb337bc35f459f3fbe 100644
--- a/Framework/Algorithms/src/ConvertUnitsUsingDetectorTable.cpp
+++ b/Framework/Algorithms/src/ConvertUnitsUsingDetectorTable.cpp
@@ -163,7 +163,7 @@ void ConvertUnitsUsingDetectorTable::exec() {
 
   // If the units conversion has flipped the ascending direction of X, reverse
   // all the vectors
-  if (outputWS->dataX(0).size() &&
+  if (!outputWS->dataX(0).empty() &&
       (outputWS->dataX(0).front() > outputWS->dataX(0).back() ||
        outputWS->dataX(m_numberOfSpectra / 2).front() >
            outputWS->dataX(m_numberOfSpectra / 2).back())) {
diff --git a/Framework/Algorithms/src/CreateTransmissionWorkspaceAuto.cpp b/Framework/Algorithms/src/CreateTransmissionWorkspaceAuto.cpp
index 6ea43bfd9ef8b81fd567cacd53ea53401e6d590e..80f938c68bd5a1f7502a43992509e0cff5320ca5 100644
--- a/Framework/Algorithms/src/CreateTransmissionWorkspaceAuto.cpp
+++ b/Framework/Algorithms/src/CreateTransmissionWorkspaceAuto.cpp
@@ -253,7 +253,7 @@ double CreateTransmissionWorkspaceAuto::checkForDefault(
   auto algProperty = this->getPointerToProperty(propName);
   if (algProperty->isDefault()) {
     auto defaults = instrument->getNumberParameter(idf_name);
-    if (defaults.size() == 0) {
+    if (defaults.empty()) {
       throw std::runtime_error("No data could be retrieved from the parameters "
                                "and argument wasn't provided: " +
                                propName);
diff --git a/Framework/Algorithms/src/CreateWorkspace.cpp b/Framework/Algorithms/src/CreateWorkspace.cpp
index e6a09e78f544665e4d69c382436d6a1e8bcfef9d..e3f866d844dbbd90261339c13b232226322bb80a 100644
--- a/Framework/Algorithms/src/CreateWorkspace.cpp
+++ b/Framework/Algorithms/src/CreateWorkspace.cpp
@@ -75,7 +75,7 @@ std::map<std::string, std::string> CreateWorkspace::validateInputs() {
   const std::string vUnit = getProperty("VerticalAxisUnit");
   const std::vector<std::string> vAxis = getProperty("VerticalAxisValues");
 
-  if (vUnit == "SpectraNumber" && vAxis.size() > 0)
+  if (vUnit == "SpectraNumber" && !vAxis.empty())
     issues["VerticalAxisValues"] =
         "Axis values cannot be provided when using a spectra axis";
 
diff --git a/Framework/Algorithms/src/DiffractionFocussing2.cpp b/Framework/Algorithms/src/DiffractionFocussing2.cpp
index f9ee393c4ea1384617716f7a17f4b7d6645885ac..97cb3d885e94d62a89b7f733323c42561baf3b24 100644
--- a/Framework/Algorithms/src/DiffractionFocussing2.cpp
+++ b/Framework/Algorithms/src/DiffractionFocussing2.cpp
@@ -493,7 +493,7 @@ void DiffractionFocussing2::execEvent() {
     }
 
     // Now you set the X axis to the X you saved before.
-    if (group2xvector.size() > 0) {
+    if (!group2xvector.empty()) {
       auto git = group2xvector.find(group);
       if (git != group2xvector.end())
         out->setX(workspaceIndex, (git->second));
diff --git a/Framework/Algorithms/src/ExtractMaskToTable.cpp b/Framework/Algorithms/src/ExtractMaskToTable.cpp
index 1ce01764bcd0e978476a6c75b86aead9c4814fe9..14a1521f75eeb3493d1e89a6513bd54dcd4f2a71 100644
--- a/Framework/Algorithms/src/ExtractMaskToTable.cpp
+++ b/Framework/Algorithms/src/ExtractMaskToTable.cpp
@@ -343,7 +343,7 @@ void ExtractMaskToTable::addToTableWorkspace(TableWorkspace_sptr outws,
   }
 
   // Exclude previously masked detectors IDs from masked detectors IDs
-  if (prevmaskedids.size() > 0) {
+  if (!prevmaskedids.empty()) {
     sort(prevmaskedids.begin(), prevmaskedids.end());
     maskeddetids = subtractVector(maskeddetids, prevmaskedids);
     numdetids = maskeddetids.size();
diff --git a/Framework/Algorithms/src/FilterEvents.cpp b/Framework/Algorithms/src/FilterEvents.cpp
index 1ca94bebd066b14bfcb4363ec18b37d42bf7c84c..af65c4c35a92fd5f176a73fc1d568e770b005cfd 100644
--- a/Framework/Algorithms/src/FilterEvents.cpp
+++ b/Framework/Algorithms/src/FilterEvents.cpp
@@ -920,7 +920,7 @@ void FilterEvents::filterEventsBySplitters(double progressamount) {
                   << "; Number of splitters = " << splitters.size() << ".\n";
 
     // Skip output workspace has ZERO splitters
-    if (splitters.size() == 0) {
+    if (splitters.empty()) {
       g_log.warning() << "[FilterEvents] Workspace " << opws->name()
                       << " Indexed @ " << wsindex
                       << " won't have logs splitted due to zero splitter size. "
diff --git a/Framework/Algorithms/src/FindPeakBackground.cpp b/Framework/Algorithms/src/FindPeakBackground.cpp
index 3c585b09f6b780e42c8f94dc1a815ff9713f0020..4481502f2ab645a7839488c4bc11e0937f29a961 100644
--- a/Framework/Algorithms/src/FindPeakBackground.cpp
+++ b/Framework/Algorithms/src/FindPeakBackground.cpp
@@ -193,7 +193,7 @@ void FindPeakBackground::exec() {
       if (mask[l] != mask[l - 1] && mask[l] == 1) {
         peaks.push_back(cont_peak());
         peaks[peaks.size() - 1].start = l + l0;
-      } else if (peaks.size() > 0) {
+      } else if (!peaks.empty()) {
         size_t ipeak = peaks.size() - 1;
         if (mask[l] != mask[l - 1] && mask[l] == 0) {
           peaks[ipeak].stop = l + l0;
@@ -205,7 +205,7 @@ void FindPeakBackground::exec() {
     size_t min_peak, max_peak;
     double a0 = 0., a1 = 0., a2 = 0.;
     int goodfit;
-    if (peaks.size() > 0) {
+    if (!peaks.empty()) {
       g_log.debug() << "Peaks' size = " << peaks.size()
                     << " -> esitmate background. \n";
       if (peaks[peaks.size() - 1].stop == 0)
@@ -225,8 +225,8 @@ void FindPeakBackground::exec() {
 
       goodfit = 2;
     }
-    estimateBackground(inpX, inpY, l0, n, min_peak, max_peak,
-                       (peaks.size() > 0), a0, a1, a2);
+    estimateBackground(inpX, inpY, l0, n, min_peak, max_peak, (!peaks.empty()),
+                       a0, a1, a2);
 
     // Add a new row
     API::TableRow t = m_outPeakTableWS->getRow(0);
diff --git a/Framework/Algorithms/src/FindPeaks.cpp b/Framework/Algorithms/src/FindPeaks.cpp
index 1b76818d6e031bd0b7792b8c4c0167ac40a0d094..482d875a7f97a2031740a8856b19648ef280567e 100644
--- a/Framework/Algorithms/src/FindPeaks.cpp
+++ b/Framework/Algorithms/src/FindPeaks.cpp
@@ -253,7 +253,7 @@ void FindPeaks::processAlgorithmProperties() {
 
   // Specified peak positions, which is optional
   m_vecPeakCentre = getProperty("PeakPositions");
-  if (m_vecPeakCentre.size() > 0)
+  if (!m_vecPeakCentre.empty())
     std::sort(m_vecPeakCentre.begin(), m_vecPeakCentre.end());
   m_vecFitWindows = getProperty("FitWindows");
 
diff --git a/Framework/Algorithms/src/FitPeak.cpp b/Framework/Algorithms/src/FitPeak.cpp
index 443e310694ce1bc901fcc0ea8067efb607c2d8b7..0b1e300373410824e1f979854cd6db9ee24263c2 100644
--- a/Framework/Algorithms/src/FitPeak.cpp
+++ b/Framework/Algorithms/src/FitPeak.cpp
@@ -195,7 +195,7 @@ void FitOneSinglePeak::setupGuessedFWHM(double usrwidth, int minfwhm,
 
   // From user specified minimum value to maximim value
   if (!fitwithsteppedfwhm) {
-    if (m_vecFWHM.size() == 0)
+    if (m_vecFWHM.empty())
       throw runtime_error("Logic error in setup guessed FWHM.  ");
     m_sstream << "No FWHM is not guessed by stepped FWHM. "
               << "\n";
@@ -1423,9 +1423,9 @@ void FitPeak::createFunctions() {
 
   // Set background function parameter values
   m_bkgdParameterNames = getProperty("BackgroundParameterNames");
-  if (usedefaultbkgdparorder && m_bkgdParameterNames.size() == 0) {
+  if (usedefaultbkgdparorder && m_bkgdParameterNames.empty()) {
     m_bkgdParameterNames = m_bkgdFunc->getParameterNames();
-  } else if (m_bkgdParameterNames.size() == 0) {
+  } else if (m_bkgdParameterNames.empty()) {
     throw runtime_error("In the non-default background parameter name mode, "
                         "user must give out parameter names. ");
   }
@@ -1456,7 +1456,7 @@ void FitPeak::createFunctions() {
 
   // Peak parameters' names
   m_peakParameterNames = getProperty("PeakParameterNames");
-  if (m_peakParameterNames.size() == 0) {
+  if (m_peakParameterNames.empty()) {
     if (defaultparorder) {
       // Use default peak parameter names' order
       m_peakParameterNames = m_peakFunc->getParameterNames();
diff --git a/Framework/Algorithms/src/FixGSASInstrumentFile.cpp b/Framework/Algorithms/src/FixGSASInstrumentFile.cpp
index 25c61f98424e1e7556be5ff123a6dcfe6fffdc61..baa214941d69c168bac345fca094078350ec3220 100644
--- a/Framework/Algorithms/src/FixGSASInstrumentFile.cpp
+++ b/Framework/Algorithms/src/FixGSASInstrumentFile.cpp
@@ -82,7 +82,7 @@ void FixGSASInstrumentFile::exec() {
     // Split "\n"
     vector<string> fields;
     boost::algorithm::split(fields, line, boost::algorithm::is_any_of("\n"));
-    if (fields.size() == 0)
+    if (fields.empty())
       throw runtime_error("Impossible to have an empty line. ");
     vec_line.push_back(fields[0]);
   }
diff --git a/Framework/Algorithms/src/GenerateEventsFilter.cpp b/Framework/Algorithms/src/GenerateEventsFilter.cpp
index 87bb497e4682531fc3b1c78b36e1f0d6f82ee5fb..22694e356958dac943693b20ed98bf2e0fa2671e 100644
--- a/Framework/Algorithms/src/GenerateEventsFilter.cpp
+++ b/Framework/Algorithms/src/GenerateEventsFilter.cpp
@@ -380,7 +380,7 @@ void GenerateEventsFilter::setFilterByTimeOnly() {
   vector<double> vec_timeintervals = this->getProperty("TimeInterval");
 
   bool singleslot = false;
-  if (vec_timeintervals.size() == 0)
+  if (vec_timeintervals.empty())
     singleslot = true;
 
   // Progress
@@ -1420,7 +1420,7 @@ void GenerateEventsFilter::makeMultipleFiltersByValuesPartialLog(
   // To fill the blanks at the end of log to make last entry of splitter is stop
   // time
   // To make it non-empty
-  if (vecSplitTime.size() == 0) {
+  if (vecSplitTime.empty()) {
     start = m_dblLog->nthTime(istart);
     stop = m_dblLog->nthTime(iend);
     lastindex = -1;
@@ -1686,7 +1686,7 @@ void GenerateEventsFilter::addNewTimeFilterSplitter(
   if (m_forFastLog) {
     // For MatrixWorkspace splitter
     // Start of splitter
-    if (m_vecSplitterTime.size() == 0) {
+    if (m_vecSplitterTime.empty()) {
       // First splitter
       m_vecSplitterTime.push_back(starttime);
     } else if (m_vecSplitterTime.back() < starttime) {
diff --git a/Framework/Algorithms/src/GeneratePeaks.cpp b/Framework/Algorithms/src/GeneratePeaks.cpp
index 41e1505e39177cc5e9e8590b8108024372406c6e..298026b1e37223fac72ab8546df368516948c457 100644
--- a/Framework/Algorithms/src/GeneratePeaks.cpp
+++ b/Framework/Algorithms/src/GeneratePeaks.cpp
@@ -748,7 +748,7 @@ API::MatrixWorkspace_sptr GeneratePeaks::createOutputWorkspace() {
 MatrixWorkspace_sptr
 GeneratePeaks::createDataWorkspace(std::vector<double> binparameters) {
   // Check validity
-  if (m_spectraSet.size() == 0)
+  if (m_spectraSet.empty())
     throw std::invalid_argument(
         "Input spectra list is empty. Unable to generate a new workspace.");
 
diff --git a/Framework/Algorithms/src/GetAllEi.cpp b/Framework/Algorithms/src/GetAllEi.cpp
index 4609e6c59ffaa363617918d6320c13f375b762b6..d09392e861a20cfe5b89e113873e8f696740c400 100644
--- a/Framework/Algorithms/src/GetAllEi.cpp
+++ b/Framework/Algorithms/src/GetAllEi.cpp
@@ -192,7 +192,7 @@ void GetAllEi::exec() {
 
   auto phase = m_chopper->getNumberParameter("initial_phase");
 
-  if (phase.size() == 0) {
+  if (phase.empty()) {
     throw std::runtime_error("Can not find initial_phase parameter"
                              " attached to the chopper-position component");
   }
@@ -250,7 +250,7 @@ void GetAllEi::exec() {
   std::vector<double> guess_opening;
 
   this->findGuessOpeningTimes(TOF_range, TOF0, Period, guess_opening);
-  if (guess_opening.size() == 0) {
+  if (guess_opening.empty()) {
     throw std::runtime_error(
         "Can not find any chopper opening time within TOF range: " +
         boost::lexical_cast<std::string>(TOF_range.first) + ':' +
@@ -858,7 +858,7 @@ void GetAllEi::findBinRanges(const MantidVec &eBins, const MantidVec &signal,
   }
   // if array decreasing rather then increasing, indexes behave differently.
   // Will it still work?
-  if (irangeMax.size() > 0) {
+  if (!irangeMax.empty()) {
     if (irangeMax[0] < irangeMin[0]) {
       irangeMax.swap(irangeMin);
     }
@@ -1022,7 +1022,7 @@ GetAllEi::getAvrgLogValue(const API::MatrixWorkspace_sptr &inputWS,
         propertyName);
   }
 
-  if (splitter.size() == 0) {
+  if (splitter.empty()) {
     auto TimeStart = inputWS->run().startTime();
     auto TimeEnd = inputWS->run().endTime();
     pTimeSeries->filterByTime(TimeStart, TimeEnd);
@@ -1193,7 +1193,7 @@ bool check_time_series_property(
   if (boost::iequals(LogName, "Defined in IDF")) {
     try {
       auto theLogs = chopper->getStringParameter(prop_name);
-      if (theLogs.size() == 0) {
+      if (theLogs.empty()) {
         if (fail)
           result[prop_name] = "Can not retrieve parameter " + prop_name +
                               " from the instrument definition file.";
diff --git a/Framework/Algorithms/src/GetDetOffsetsMultiPeaks.cpp b/Framework/Algorithms/src/GetDetOffsetsMultiPeaks.cpp
index 89a8d1b264e353f82c4f4b14dc9ab8fe83e2be00..ced49ee642a3bf435586fe31737758bbcf060bff 100644
--- a/Framework/Algorithms/src/GetDetOffsetsMultiPeaks.cpp
+++ b/Framework/Algorithms/src/GetDetOffsetsMultiPeaks.cpp
@@ -293,7 +293,7 @@ void GetDetOffsetsMultiPeaks::processProperties() {
 
   // the peak positions and where to fit
   m_peakPositions = getProperty("DReference");
-  if (m_peakPositions.size() == 0)
+  if (m_peakPositions.empty())
     throw std::runtime_error("There is no input referenced peak position.");
   std::sort(m_peakPositions.begin(), m_peakPositions.end());
 
@@ -324,7 +324,7 @@ void GetDetOffsetsMultiPeaks::processProperties() {
 
     g_log.information(infoss.str());
 
-    if (m_fitWindows.size() == 0)
+    if (m_fitWindows.empty())
       g_log.warning() << "Input FitWindowMaxWidth = " << maxwidth
                       << "  No FitWidows will be generated."
                       << "\n";
@@ -423,7 +423,7 @@ void GetDetOffsetsMultiPeaks::importFitWindowTableWorkspace(
     if (spec < 0 && founduniversal) {
       throw std::runtime_error("There are more than 1 universal spectrum (spec "
                                "< 0) in TableWorkspace.");
-    } else if (spec >= 0 && m_vecFitWindow[spec].size() != 0) {
+    } else if (spec >= 0 && !m_vecFitWindow[spec].empty()) {
       std::stringstream ess;
       ess << "Peak fit windows at row " << i << " has spectrum " << spec
           << ", which appears before in fit window table workspace. ";
@@ -455,7 +455,7 @@ void GetDetOffsetsMultiPeaks::importFitWindowTableWorkspace(
   } else if (founduniversal) {
     // Fill the universal
     for (size_t i = 0; i < m_inputWS->getNumberHistograms(); ++i)
-      if (m_vecFitWindow[i].size() == 0)
+      if (m_vecFitWindow[i].empty())
         m_vecFitWindow[i] = vec_univFitWindow;
   }
 
diff --git a/Framework/Algorithms/src/MaskBins.cpp b/Framework/Algorithms/src/MaskBins.cpp
index 5400e3c05bd2820e10bf44c3100acf4b9f11a8f5..30110ebb23e86d26c59d48f592096ea7289b568e 100644
--- a/Framework/Algorithms/src/MaskBins.cpp
+++ b/Framework/Algorithms/src/MaskBins.cpp
@@ -77,7 +77,7 @@ void MaskBins::exec() {
   //---------------------------------------------------------------------------------
   // what spectra (workspace indices) to load. Optional.
   this->spectra_list = this->getProperty("SpectraList");
-  if (this->spectra_list.size() > 0) {
+  if (!this->spectra_list.empty()) {
     const int numHist = static_cast<int>(inputWS->getNumberHistograms());
     //--- Validate spectra list ---
     for (auto wi : this->spectra_list) {
@@ -123,7 +123,7 @@ void MaskBins::exec() {
     // Parallel running has problems with a race condition, leading to
     // occaisional test failures and crashes
 
-    bool useSpectraList = (this->spectra_list.size() > 0);
+    bool useSpectraList = (!this->spectra_list.empty());
 
     // Alter the for loop ending based on what we are looping on
     int for_end = numHists;
@@ -172,7 +172,7 @@ void MaskBins::execEvent() {
   outputWS->sortAll(Mantid::DataObjects::TOF_SORT, &progress);
 
   // Go through all histograms
-  if (this->spectra_list.size() > 0) {
+  if (!this->spectra_list.empty()) {
     // Specific spectra were specified
     PARALLEL_FOR1(outputWS)
     for (int i = 0; i < static_cast<int>(this->spectra_list.size()); ++i) {
diff --git a/Framework/Algorithms/src/MaskBinsFromTable.cpp b/Framework/Algorithms/src/MaskBinsFromTable.cpp
index d8f25495f978d19689bc65db6ed4f09da82bad67..b848e0439de26a168d1ffcfebb78d053cb6269c9 100644
--- a/Framework/Algorithms/src/MaskBinsFromTable.cpp
+++ b/Framework/Algorithms/src/MaskBinsFromTable.cpp
@@ -252,7 +252,7 @@ MaskBinsFromTable::convertToSpectraList(API::MatrixWorkspace_sptr dataws,
   }
 
   // Sort the vector
-  if (wsindexvec.size() == 0)
+  if (wsindexvec.empty())
     throw runtime_error("There is no spectrum found for input detectors list.");
 
   sort(wsindexvec.begin(), wsindexvec.end());
diff --git a/Framework/Algorithms/src/MergeRuns.cpp b/Framework/Algorithms/src/MergeRuns.cpp
index 158aa8d0d95e993c159ca1662d55271d6ac29883..2b6882980516825d6310a2bb7958f2ceebe51c21 100644
--- a/Framework/Algorithms/src/MergeRuns.cpp
+++ b/Framework/Algorithms/src/MergeRuns.cpp
@@ -133,7 +133,7 @@ void MergeRuns::exec() {
  * Throws an error if there is any incompatibility.
  */
 void MergeRuns::buildAdditionTables() {
-  if (m_inEventWS.size() <= 0)
+  if (m_inEventWS.empty())
     throw std::invalid_argument("MergeRuns: No workspaces found to merge.");
 
   // This'll hold the addition tables.
diff --git a/Framework/Algorithms/src/MuonGroupDetectors.cpp b/Framework/Algorithms/src/MuonGroupDetectors.cpp
index 3bc6963fcb0cf2dc4158ce11c18a07accce7c222..a2b2edca4ded9e948e77749802b8086241dee071 100644
--- a/Framework/Algorithms/src/MuonGroupDetectors.cpp
+++ b/Framework/Algorithms/src/MuonGroupDetectors.cpp
@@ -73,11 +73,11 @@ void MuonGroupDetectors::exec() {
 
   // First pass to determine how many non-empty groups we have
   for (size_t row = 0; row < table->rowCount(); ++row) {
-    if (table->cell<std::vector<int>>(row, 0).size() != 0)
+    if (!table->cell<std::vector<int>>(row, 0).empty())
       nonEmptyRows.push_back(row);
   }
 
-  if (nonEmptyRows.size() == 0)
+  if (nonEmptyRows.empty())
     throw std::invalid_argument(
         "Detector Grouping Table doesn't contain any non-empty groups");
 
diff --git a/Framework/Algorithms/src/PerformIndexOperations.cpp b/Framework/Algorithms/src/PerformIndexOperations.cpp
index 0ed841acc3d53698253a939c30336986f9d28690..7613d5d8f20f00a2d862d53cc09beb2ad00ce38c 100644
--- a/Framework/Algorithms/src/PerformIndexOperations.cpp
+++ b/Framework/Algorithms/src/PerformIndexOperations.cpp
@@ -72,7 +72,7 @@ public:
 
   MatrixWorkspace_sptr execute(MatrixWorkspace_sptr inputWS) const override {
     MatrixWorkspace_sptr outWS;
-    if (m_indexes.size() > 0) {
+    if (!m_indexes.empty()) {
       Mantid::API::AlgorithmManagerImpl &factory =
           Mantid::API::AlgorithmManager::Instance();
       auto sumSpectraAlg = factory.create("SumSpectra");
diff --git a/Framework/Algorithms/src/PlotAsymmetryByLogValue.cpp b/Framework/Algorithms/src/PlotAsymmetryByLogValue.cpp
index 42ca93d80e8a0f36043d558a94320c08df85981b..b8899accdc3a41612e45eaa1bc4b78de6148da42 100644
--- a/Framework/Algorithms/src/PlotAsymmetryByLogValue.cpp
+++ b/Framework/Algorithms/src/PlotAsymmetryByLogValue.cpp
@@ -174,7 +174,7 @@ void PlotAsymmetryByLogValue::exec() {
   }
 
   // Create the 2D workspace for the output
-  int nplots = m_greenY.size() ? 4 : 1;
+  int nplots = !m_greenY.empty() ? 4 : 1;
   size_t npoints = m_logValue.size();
   MatrixWorkspace_sptr outWS = WorkspaceFactory::Instance().create(
       "Workspace2D",
diff --git a/Framework/Algorithms/src/ReflectometryReductionOneAuto.cpp b/Framework/Algorithms/src/ReflectometryReductionOneAuto.cpp
index fd381c3bc25c532b6161940088b0157b2bc2df58..13eb6c9b10ef254c31711ebfc77aace3d06e8e0c 100644
--- a/Framework/Algorithms/src/ReflectometryReductionOneAuto.cpp
+++ b/Framework/Algorithms/src/ReflectometryReductionOneAuto.cpp
@@ -501,7 +501,7 @@ double ReflectometryReductionOneAuto::checkForDefault(
   auto algProperty = this->getPointerToProperty(propName);
   if (algProperty->isDefault()) {
     auto defaults = instrument->getNumberParameter(idf_name);
-    if (defaults.size() == 0) {
+    if (defaults.empty()) {
       throw std::runtime_error("No data could be retrieved from the parameters "
                                "and argument wasn't provided: " +
                                propName);
diff --git a/Framework/Algorithms/src/RenameWorkspaces.cpp b/Framework/Algorithms/src/RenameWorkspaces.cpp
index 714d422cccd2ed0be1f78be8e78377fe3e5555a8..672daee0960323c7b82443d62ea32590c351c687 100644
--- a/Framework/Algorithms/src/RenameWorkspaces.cpp
+++ b/Framework/Algorithms/src/RenameWorkspaces.cpp
@@ -53,11 +53,11 @@ void RenameWorkspaces::exec() {
   std::string suffix = getPropertyValue("Suffix");
 
   // Check properties
-  if (newWsName.size() == 0 && prefix == "" && suffix == "") {
+  if (newWsName.empty() && prefix == "" && suffix == "") {
     throw std::invalid_argument(
         "No list of Workspace names, prefix or suffix has been supplied.");
   }
-  if (newWsName.size() > 0 && (prefix != "" || suffix != "")) {
+  if (!newWsName.empty() && (prefix != "" || suffix != "")) {
     throw std::invalid_argument("Both a list of workspace names and a prefix "
                                 "or suffix has been supplied.");
   }
@@ -73,7 +73,7 @@ void RenameWorkspaces::exec() {
   }
 
   size_t nWs = inputWsName.size();
-  if (newWsName.size() > 0) {
+  if (!newWsName.empty()) {
     // We are using a list of new names
     if (nWs > newWsName.size()) {
       nWs = newWsName.size();
diff --git a/Framework/Algorithms/src/SetInstrumentParameter.cpp b/Framework/Algorithms/src/SetInstrumentParameter.cpp
index 79455512ca367e0aacd0d4472a1a69a4e66879b3..556186a2929737776fff56cc120c2178b61b1fde 100644
--- a/Framework/Algorithms/src/SetInstrumentParameter.cpp
+++ b/Framework/Algorithms/src/SetInstrumentParameter.cpp
@@ -106,7 +106,7 @@ void SetInstrumentParameter::exec() {
       addParameter(paramMap, det.get(), paramName, paramType, paramValue);
     }
   } else {
-    if (cmptList.size() > 0) {
+    if (!cmptList.empty()) {
       for (auto &cmpt : cmptList) {
         addParameter(paramMap, cmpt.get(), paramName, paramType, paramValue);
       }
diff --git a/Framework/Algorithms/src/SpatialGrouping.cpp b/Framework/Algorithms/src/SpatialGrouping.cpp
index 414d5c5359427cce97d71b764f0f54fd46a05ed5..001ebed33df63deeb596e24a9ea8a66fcdc4fb14 100644
--- a/Framework/Algorithms/src/SpatialGrouping.cpp
+++ b/Framework/Algorithms/src/SpatialGrouping.cpp
@@ -135,7 +135,7 @@ void SpatialGrouping::exec() {
     m_groups.push_back(group);
   }
 
-  if (m_groups.size() == 0) {
+  if (m_groups.empty()) {
     g_log.warning() << "No groups generated." << std::endl;
     return;
   }
diff --git a/Framework/Algorithms/src/Stitch1DMany.cpp b/Framework/Algorithms/src/Stitch1DMany.cpp
index de3a34b42ba93a3a3373a568896aec1a5e424fce..ac33223869f903a578eea16a2a5916575528a5c7 100644
--- a/Framework/Algorithms/src/Stitch1DMany.cpp
+++ b/Framework/Algorithms/src/Stitch1DMany.cpp
@@ -85,7 +85,7 @@ std::map<std::string, std::string> Stitch1DMany::validateInputs() {
   }
 
   // Check that all the workspaces are of the same type
-  if (m_inputWorkspaces.size() > 0) {
+  if (!m_inputWorkspaces.empty()) {
     const std::string id = m_inputWorkspaces[0]->id();
     for (auto &inputWorkspace : m_inputWorkspaces) {
       if (inputWorkspace->id() != id) {
@@ -118,8 +118,7 @@ std::map<std::string, std::string> Stitch1DMany::validateInputs() {
   m_startOverlaps = this->getProperty("StartOverlaps");
   m_endOverlaps = this->getProperty("EndOverlaps");
 
-  if (m_startOverlaps.size() > 0 &&
-      m_startOverlaps.size() != m_numWorkspaces - 1)
+  if (!m_startOverlaps.empty() && m_startOverlaps.size() != m_numWorkspaces - 1)
     errors["StartOverlaps"] = "If given, StartOverlaps must have one fewer "
                               "entries than the number of input workspaces.";
 
@@ -132,7 +131,7 @@ std::map<std::string, std::string> Stitch1DMany::validateInputs() {
   m_manualScaleFactor = this->getProperty("ManualScaleFactor");
   m_params = this->getProperty("Params");
 
-  if (m_params.size() < 1)
+  if (m_params.empty())
     errors["Params"] = "At least one parameter must be given.";
 
   if (!m_scaleRHSWorkspace) {
diff --git a/Framework/Algorithms/src/UpdateScriptRepository.cpp b/Framework/Algorithms/src/UpdateScriptRepository.cpp
index c6b2a587a5957fa7f48286622efee2b64b6e3940..e34d24ccb9e35e686f0afa2875ef24fa265d9bc3 100644
--- a/Framework/Algorithms/src/UpdateScriptRepository.cpp
+++ b/Framework/Algorithms/src/UpdateScriptRepository.cpp
@@ -54,7 +54,7 @@ void UpdateScriptRepository::exec() {
     return; // it means that the ScriptRepository was not installed.
 
   std::vector<std::string> f_list = repo_ptr->check4Update();
-  if (f_list.size() > 0) {
+  if (!f_list.empty()) {
     std::stringstream info;
     info << "Information about ScriptRepository:\n"
          << " A more recent version of the following files was installed:\n";
diff --git a/Framework/Crystal/inc/MantidCrystal/FindSXPeaks.h b/Framework/Crystal/inc/MantidCrystal/FindSXPeaks.h
index 9369716ccad532dd7749da018f5b3f747cdcb073..81f67fd8d4a984400d852d717297598258f5b1dc 100644
--- a/Framework/Crystal/inc/MantidCrystal/FindSXPeaks.h
+++ b/Framework/Crystal/inc/MantidCrystal/FindSXPeaks.h
@@ -33,7 +33,7 @@ public:
     if (intensity < 0) {
       throw std::invalid_argument("SXPeak: Cannot have an intensity < 0");
     }
-    if (spectral.size() == 0) {
+    if (spectral.empty()) {
       throw std::invalid_argument(
           "SXPeak: Cannot have zero sized spectral list");
     }
diff --git a/Framework/Crystal/inc/MantidCrystal/IndexSXPeaks.h b/Framework/Crystal/inc/MantidCrystal/IndexSXPeaks.h
index 23d86a048562f7ffb7e4fc7164d89353bdd0a5d4..2d93cc4fba82fe71b73df5261ca4ab2f3836ed6c 100644
--- a/Framework/Crystal/inc/MantidCrystal/IndexSXPeaks.h
+++ b/Framework/Crystal/inc/MantidCrystal/IndexSXPeaks.h
@@ -101,7 +101,7 @@ public:
     _hkls = s;
   }
   void setFirst() {
-    if (_hkls.size() > 0) {
+    if (!_hkls.empty()) {
       auto it = _hkls.begin(); // Take the first possiblity
       it++;
       _hkls.erase(it, _hkls.end()); // Erase all others!
diff --git a/Framework/Crystal/src/AnvredCorrection.cpp b/Framework/Crystal/src/AnvredCorrection.cpp
index 5ab009d0c6cae96fb3e9ec7ade26d33d21cdb692..af9a61ecee54864d6b01d8271c85cc6991f314de 100644
--- a/Framework/Crystal/src/AnvredCorrection.cpp
+++ b/Framework/Crystal/src/AnvredCorrection.cpp
@@ -553,8 +553,8 @@ void AnvredCorrection::BuildLamdaWeights() {
 
   // GetSpectrumWeights( spectrum_file_name, m_lamda_weight);
 
-  if (m_lamda_weight.size() == 0) // loading spectrum failed so use
-  {                               // array of 1's
+  if (m_lamda_weight.empty()) // loading spectrum failed so use
+  {                           // array of 1's
     //    power = power_ns;                      // This is commented out, so we
     // don't override user specified
     // value.
diff --git a/Framework/Crystal/src/Cluster.cpp b/Framework/Crystal/src/Cluster.cpp
index 60cb15a1cb76792bc9d12b8d712219c86102dcb8..b64629b5be1a2a832843a2a4806c3a574a287e13 100644
--- a/Framework/Crystal/src/Cluster.cpp
+++ b/Framework/Crystal/src/Cluster.cpp
@@ -84,7 +84,7 @@ Cluster::integrate(Mantid::API::IMDHistoWorkspace_const_sptr ws) const {
  * @param disjointSet
  */
 void Cluster::toUniformMinimum(VecElements &disjointSet) {
-  if (m_indexes.size() > 0) {
+  if (!m_indexes.empty()) {
     size_t parentIndex = m_rootCluster->getRepresentitiveIndex();
 
     for (size_t i = 1; i < m_indexes.size(); ++i) {
diff --git a/Framework/Crystal/src/IntegratePeakTimeSlices.cpp b/Framework/Crystal/src/IntegratePeakTimeSlices.cpp
index 3684edd154afe64750b68192a1192144d1599840..0790a4dfaaafc028dc25c444aaae181456ab3abc 100644
--- a/Framework/Crystal/src/IntegratePeakTimeSlices.cpp
+++ b/Framework/Crystal/src/IntegratePeakTimeSlices.cpp
@@ -494,7 +494,7 @@ void IntegratePeakTimeSlices::exec() {
               auto XXX =
                   boost::make_shared<DataModeHandler>(*m_AttributeValues);
               m_AttributeValues = XXX;
-              if (X.size() > 0)
+              if (!X.empty())
                 m_AttributeValues->setTime((X[chanMax] + X[chanMin]) / 2.0);
 
             } else // lastAttributeList exists
@@ -2391,7 +2391,7 @@ bool DataModeHandler::IsEnoughData(const double *ParameterValues,
   // Check if flat
   double Varx, Vary, Cov;
 
-  if (StatBase.size() <= 0)
+  if (StatBase.empty())
     return false;
 
   double ncells = static_cast<int>(StatBase[IIntensities]);
diff --git a/Framework/Crystal/src/SortHKL.cpp b/Framework/Crystal/src/SortHKL.cpp
index b70c93222949d18fe63014c97ca80d831644ec32..09c736aa0d7633905af6f3d12552e8569bf89af7 100644
--- a/Framework/Crystal/src/SortHKL.cpp
+++ b/Framework/Crystal/src/SortHKL.cpp
@@ -82,7 +82,7 @@ void SortHKL::exec() {
   const std::vector<Peak> &inputPeaks = inputPeaksWorkspace->getPeaks();
   std::vector<Peak> peaks = getNonZeroPeaks(inputPeaks);
 
-  if (peaks.size() == 0) {
+  if (peaks.empty()) {
     g_log.error() << "Number of peaks should not be 0 for SortHKL.\n";
     return;
   }
@@ -329,7 +329,7 @@ double PeaksStatistics::getRMS(const std::vector<double> &data) const {
 /// Returns the lowest and hights wavelength in the peak list.
 std::pair<double, double>
 PeaksStatistics::getLambdaLimits(const std::vector<Peak> &peaks) const {
-  if (peaks.size() == 0) {
+  if (peaks.empty()) {
     return std::make_pair(0.0, 0.0);
   }
 
@@ -502,7 +502,7 @@ void UniqueReflection::removeOutliers(double sigmaCritical) {
       }
     }
 
-    if (outlierIndices.size() > 0) {
+    if (!outlierIndices.empty()) {
       for (auto it = outlierIndices.rbegin(); it != outlierIndices.rend();
            ++it) {
         m_peaks.erase(m_peaks.begin() + (*it));
diff --git a/Framework/CurveFitting/src/Algorithms/FitPowderDiffPeaks.cpp b/Framework/CurveFitting/src/Algorithms/FitPowderDiffPeaks.cpp
index b6e7a99e935832d2575600bd53d969981d26b9b4..5118bac9b219817dcfee78f121fbddbdbfabaee9 100644
--- a/Framework/CurveFitting/src/Algorithms/FitPowderDiffPeaks.cpp
+++ b/Framework/CurveFitting/src/Algorithms/FitPowderDiffPeaks.cpp
@@ -339,8 +339,7 @@ void FitPowderDiffPeaks::processInputProperties() {
   m_rightmostPeakRightBound = getProperty("RightMostPeakRightBound");
 
   if (m_fitMode == ROBUSTFIT) {
-    if (m_rightmostPeakHKL.size() == 0 ||
-        m_rightmostPeakLeftBound == EMPTY_DBL() ||
+    if (m_rightmostPeakHKL.empty() || m_rightmostPeakLeftBound == EMPTY_DBL() ||
         m_rightmostPeakRightBound == EMPTY_DBL()) {
       stringstream errss;
       errss << "If fit mode is 'RobustFit', then user must specify all 3 "
@@ -758,7 +757,7 @@ bool FitPowderDiffPeaks::fitSinglePeakRobust(
                  << peakinfob1 << endl;
 
   // c) Fit peak parameters by the value from right peak
-  if (rightpeakparammap.size() > 0) {
+  if (!rightpeakparammap.empty()) {
     restoreFunctionParameters(peak, rightpeakparammap);
     peak->setParameter("X0", tof_h);
     peak->setParameter("I", height * fwhm);
diff --git a/Framework/CurveFitting/src/Algorithms/LeBailFit.cpp b/Framework/CurveFitting/src/Algorithms/LeBailFit.cpp
index 0ef5f1dcee13c7b3088ff972f837a17c8354f980..a0c58255498a79d041f80a1251828d2516838a64 100644
--- a/Framework/CurveFitting/src/Algorithms/LeBailFit.cpp
+++ b/Framework/CurveFitting/src/Algorithms/LeBailFit.cpp
@@ -748,7 +748,7 @@ void LeBailFit::createLeBailFunction() {
       boost::make_shared<LeBailFunction>(LeBailFunction(m_peakType));
 
   // Set up profile parameters
-  if (m_funcParameters.size() == 0)
+  if (m_funcParameters.empty())
     throw runtime_error("Function parameters must be set up by this point.");
 
   map<string, double> pardblmap = convertToDoubleMap(m_funcParameters);
@@ -2094,7 +2094,7 @@ bool LeBailFit::calculateDiffractionPattern(const MantidVec &vecX,
       ::transform(values.begin(), values.end(), vecBkgd.begin(), values.begin(),
                   ::plus<double>());
     } else {
-      if (veccalbkgd.size() == 0)
+      if (veccalbkgd.empty())
         throw runtime_error("Programming logic error.");
       ::transform(values.begin(), values.end(), veccalbkgd.begin(),
                   values.begin(), ::plus<double>());
@@ -2113,7 +2113,7 @@ bool LeBailFit::calculateDiffractionPattern(const MantidVec &vecX,
                      caldata.begin(), std::plus<double>());
     } else {
       // Re-calculate background
-      if (veccalbkgd.size() == 0)
+      if (veccalbkgd.empty())
         throw runtime_error("Programming logic error (2). ");
       std::transform(values.begin(), values.end(), veccalbkgd.begin(),
                      caldata.begin(), std::plus<double>());
@@ -2401,7 +2401,7 @@ void LeBailFit::bookKeepBestMCResult(map<string, Parameter> parammap,
     m_bestMCStep = istep;
 
     // b) Record parameters
-    if (m_bestParameters.size() == 0) {
+    if (m_bestParameters.empty()) {
       // If not be initialized, initialize it!
       m_bestParameters = parammap;
     } else {
diff --git a/Framework/CurveFitting/src/Algorithms/LeBailFunction.cpp b/Framework/CurveFitting/src/Algorithms/LeBailFunction.cpp
index f9b594569d6099f9570b9ca4d12fd6e0a3d086d1..c8a4a58dc70505c74298642bd43bf315f00a56f9 100644
--- a/Framework/CurveFitting/src/Algorithms/LeBailFunction.cpp
+++ b/Framework/CurveFitting/src/Algorithms/LeBailFunction.cpp
@@ -835,7 +835,7 @@ void LeBailFunction::groupPeaks(
                           << " causes grouping "
                           << "peak over at maximum TOF = " << xmax << ".\n";
 
-      if (peakgroup.size() > 0) {
+      if (!peakgroup.empty()) {
         vector<pair<double, IPowderDiffPeakFunction_sptr>> peakgroupcopy =
             peakgroup;
         peakgroupvec.push_back(peakgroupcopy);
diff --git a/Framework/CurveFitting/src/Algorithms/RefinePowderInstrumentParameters3.cpp b/Framework/CurveFitting/src/Algorithms/RefinePowderInstrumentParameters3.cpp
index 1e0dd4ec34ae7da9a679286e1dc51f2950d618a9..33990e18619dc7764421c65985cc593b62b793a6 100644
--- a/Framework/CurveFitting/src/Algorithms/RefinePowderInstrumentParameters3.cpp
+++ b/Framework/CurveFitting/src/Algorithms/RefinePowderInstrumentParameters3.cpp
@@ -662,7 +662,7 @@ void RefinePowderInstrumentParameters3::bookKeepMCResult(
   }
 
   // 2. Record for the best parameters
-  if (bestparammap.size() == 0) {
+  if (bestparammap.empty()) {
     // No record yet
     duplicateParameters(parammap, bestparammap);
   } else if (recordparameter) {
@@ -796,7 +796,7 @@ void RefinePowderInstrumentParameters3::addParameterToMCMinimize(
 double RefinePowderInstrumentParameters3::calculateFunction(
     map<string, Parameter> parammap, vector<double> &vecY) {
   // 1. Implement parameter values to m_positionFunc
-  if (parammap.size() > 0)
+  if (!parammap.empty())
     setFunctionParameterValues(m_positionFunc, parammap);
 
   // 2. Calculate
diff --git a/Framework/CurveFitting/src/Functions/DiffRotDiscreteCircle.cpp b/Framework/CurveFitting/src/Functions/DiffRotDiscreteCircle.cpp
index f295573909e3ba7653a4aad0a806f57f97d95496..1f0aa47943c59266cabbe70d654123e4ca2a565d 100644
--- a/Framework/CurveFitting/src/Functions/DiffRotDiscreteCircle.cpp
+++ b/Framework/CurveFitting/src/Functions/DiffRotDiscreteCircle.cpp
@@ -105,7 +105,7 @@ void InelasticDiffRotDiscreteCircle::function1D(double *out,
 
   double Q;
   if (getAttribute("Q").asDouble() == EMPTY_DBL()) {
-    if (m_qValueCache.size() == 0) {
+    if (m_qValueCache.empty()) {
       throw std::runtime_error(
           "No Q attribute provided and cannot retrieve from worksapce.");
     }
diff --git a/Framework/CurveFitting/src/Functions/DiffSphere.cpp b/Framework/CurveFitting/src/Functions/DiffSphere.cpp
index 22d2e0f8baa899ce887ef6783b8d966b3abe4828..d1af5ca9a3367e3b1eeedee0f247021b7fa33e97 100644
--- a/Framework/CurveFitting/src/Functions/DiffSphere.cpp
+++ b/Framework/CurveFitting/src/Functions/DiffSphere.cpp
@@ -216,7 +216,7 @@ void InelasticDiffSphere::function1D(double *out, const double *xValues,
 
   double Q;
   if (getAttribute("Q").asDouble() == EMPTY_DBL()) {
-    if (m_qValueCache.size() == 0) {
+    if (m_qValueCache.empty()) {
       throw std::runtime_error(
           "No Q attribute provided and cannot retrieve from worksapce.");
     }
diff --git a/Framework/CurveFitting/src/Functions/ProcessBackground.cpp b/Framework/CurveFitting/src/Functions/ProcessBackground.cpp
index eb00fefa1a46df91adb40dccc71b4bddf587532c..852d9c90744a4cb4e5eb8ba391c9fb7b703b1260 100644
--- a/Framework/CurveFitting/src/Functions/ProcessBackground.cpp
+++ b/Framework/CurveFitting/src/Functions/ProcessBackground.cpp
@@ -936,7 +936,7 @@ void RemovePeaks::setup(TableWorkspace_sptr peaktablews) {
   // Check
   if (m_vecPeakCentre.size() != m_vecPeakFWHM.size())
     throw runtime_error("Number of peak centres and FWHMs are different!");
-  else if (m_vecPeakCentre.size() == 0)
+  else if (m_vecPeakCentre.empty())
     throw runtime_error(
         "There is not any peak entry in input table workspace.");
 
@@ -950,7 +950,7 @@ Workspace2D_sptr
 RemovePeaks::removePeaks(API::MatrixWorkspace_const_sptr dataws, int wsindex,
                          double numfwhm) {
   // Check
-  if (m_vecPeakCentre.size() == 0)
+  if (m_vecPeakCentre.empty())
     throw runtime_error("RemovePeaks has not been setup yet. ");
 
   // Initialize vectors
diff --git a/Framework/DataHandling/inc/MantidDataHandling/LoadEventNexus.h b/Framework/DataHandling/inc/MantidDataHandling/LoadEventNexus.h
index b0eba695946b2ff2f6c8b6789e9f621db059239e..50817aa6764f881f8a948637835825b7748615d0 100644
--- a/Framework/DataHandling/inc/MantidDataHandling/LoadEventNexus.h
+++ b/Framework/DataHandling/inc/MantidDataHandling/LoadEventNexus.h
@@ -483,7 +483,7 @@ void LoadEventNexus::loadEntryMetadata(const std::string &nexusfilename, T WS,
     // inside ISIS the run_number type is int32
     std::vector<int> value;
     file.getData(value);
-    if (value.size() > 0)
+    if (!value.empty())
       run = boost::lexical_cast<std::string>(value[0]);
   }
   if (!run.empty()) {
diff --git a/Framework/DataHandling/src/DownloadInstrument.cpp b/Framework/DataHandling/src/DownloadInstrument.cpp
index 2ac3f74bca8f6a91d9014482fc3d410230627171..c1b1b41bccf900e265dc7baca2f61e3d7d70c682 100644
--- a/Framework/DataHandling/src/DownloadInstrument.cpp
+++ b/Framework/DataHandling/src/DownloadInstrument.cpp
@@ -99,7 +99,7 @@ void DownloadInstrument::exec() {
     return;
   }
 
-  if (fileMap.size() == 0) {
+  if (fileMap.empty()) {
     g_log.notice("All instrument definitions up to date");
   } else {
     std::string s = (fileMap.size() > 1) ? "s" : "";
diff --git a/Framework/DataHandling/src/FilterEventsByLogValuePreNexus.cpp b/Framework/DataHandling/src/FilterEventsByLogValuePreNexus.cpp
index 5141c46c1497eca62ea07bca75080ccc1a508b8d..a1c6a3bf6fa1f42e9adee7597b0cf2a342596c99 100644
--- a/Framework/DataHandling/src/FilterEventsByLogValuePreNexus.cpp
+++ b/Framework/DataHandling/src/FilterEventsByLogValuePreNexus.cpp
@@ -508,7 +508,7 @@ void FilterEventsByLogValuePreNexus::processProperties() {
   // Load partial spectra
   //---------------------------------------------------------------------------
   // For slight speed up
-  m_loadOnlySomeSpectra = (this->m_spectraList.size() > 0);
+  m_loadOnlySomeSpectra = (!this->m_spectraList.empty());
 
   // Turn the spectra list into a map, for speed of access
   for (auto spectra : m_spectraList)
diff --git a/Framework/DataHandling/src/LoadCanSAS1D2.cpp b/Framework/DataHandling/src/LoadCanSAS1D2.cpp
index 2d5d46d0e2457e7717de4c5f95ec5cc2534cd996..f3029ed23b08d987d1ebb99ef45a8e1c1995880f 100644
--- a/Framework/DataHandling/src/LoadCanSAS1D2.cpp
+++ b/Framework/DataHandling/src/LoadCanSAS1D2.cpp
@@ -57,7 +57,7 @@ void LoadCanSAS1D2::exec() {
   if (!loadTrans)
     return; // all done. It is not to load the transmission, nor check if it
             // exists.
-  if (trans_gp.size() == 0 && trans_can_gp.size() == 0) {
+  if (trans_gp.empty() && trans_can_gp.empty()) {
     return; // all done, not transmission inside
   }
 
diff --git a/Framework/DataHandling/src/LoadDetectorsGroupingFile.cpp b/Framework/DataHandling/src/LoadDetectorsGroupingFile.cpp
index 70835d1a5b9623bd96fd3480a911524adb99857f..dbb90966f97961635a922608f5add353135979d2 100644
--- a/Framework/DataHandling/src/LoadDetectorsGroupingFile.cpp
+++ b/Framework/DataHandling/src/LoadDetectorsGroupingFile.cpp
@@ -109,7 +109,7 @@ void LoadDetectorsGroupingFile::exec() {
       std::map<int, std::vector<detid_t>>::iterator dit;
       for (dit = m_groupDetectorsMap.begin(); dit != m_groupDetectorsMap.end();
            ++dit) {
-        if (dit->second.size() > 0)
+        if (!dit->second.empty())
           throw std::invalid_argument(
               "Grouping file specifies detector ID without instrument name");
       }
@@ -192,7 +192,7 @@ void LoadDetectorsGroupingFile::setByComponents() {
     bool norecord = true;
     for (mapiter = m_groupComponentsMap.begin();
          mapiter != m_groupComponentsMap.end(); ++mapiter) {
-      if (mapiter->second.size() > 0) {
+      if (!mapiter->second.empty()) {
         g_log.error() << "Instrument is not specified in XML file.  "
                       << "But tag 'component' is used in XML file for Group "
                       << mapiter->first << " It is not allowed" << std::endl;
@@ -262,12 +262,12 @@ void LoadDetectorsGroupingFile::setByComponents() {
 void LoadDetectorsGroupingFile::setByDetectors() {
 
   // 0. Check
-  if (!m_instrument && m_groupDetectorsMap.size() > 0) {
+  if (!m_instrument && !m_groupDetectorsMap.empty()) {
     std::map<int, std::vector<detid_t>>::iterator mapiter;
     bool norecord = true;
     for (mapiter = m_groupDetectorsMap.begin();
          mapiter != m_groupDetectorsMap.end(); ++mapiter)
-      if (mapiter->second.size() > 0) {
+      if (!mapiter->second.empty()) {
         norecord = false;
         g_log.error() << "Instrument is not specified in XML file. "
                       << "But tag 'detid' is used in XML file for Group "
diff --git a/Framework/DataHandling/src/LoadEventNexus.cpp b/Framework/DataHandling/src/LoadEventNexus.cpp
index 7c725b16cde04fe603e6e4820fd1e137f549f76f..b170d1fe5a65b13404a6d72fe6d5d9d86dea3a43 100644
--- a/Framework/DataHandling/src/LoadEventNexus.cpp
+++ b/Framework/DataHandling/src/LoadEventNexus.cpp
@@ -515,7 +515,7 @@ public:
     std::string thisStartTime = "";
     size_t thisNumPulses = 0;
     file.getAttr("offset", thisStartTime);
-    if (file.getInfo().dims.size() > 0)
+    if (!file.getInfo().dims.empty())
       thisNumPulses = file.getInfo().dims[0];
     file.closeData();
 
@@ -2149,7 +2149,7 @@ void LoadEventNexus::deleteBanks(EventWorkspaceCollection_sptr workspace,
       }
     }
   }
-  if (detList.size() == 0)
+  if (detList.empty())
     return;
   for (auto &det : detList) {
     bool keep = false;
diff --git a/Framework/DataHandling/src/LoadEventPreNexus.cpp b/Framework/DataHandling/src/LoadEventPreNexus.cpp
index 88b708e69ee18722524f828755991804e58899b1..3cca51ed76797b9da07ad6b1f7d57d724e05be92 100644
--- a/Framework/DataHandling/src/LoadEventPreNexus.cpp
+++ b/Framework/DataHandling/src/LoadEventPreNexus.cpp
@@ -476,7 +476,7 @@ void LoadEventPreNexus::procEvents(
   }
 
   // For slight speed up
-  loadOnlySomeSpectra = (this->spectra_list.size() > 0);
+  loadOnlySomeSpectra = (!this->spectra_list.empty());
 
   // Turn the spectra list into a map, for speed of access
   for (auto &spectrum : spectra_list)
diff --git a/Framework/DataHandling/src/LoadEventPreNexus2.cpp b/Framework/DataHandling/src/LoadEventPreNexus2.cpp
index 3bbd5f6e04614c77173035c5ba42c42b188a93b6..c92f4fd603a4239a9a7a680f5c186db086ee4a23 100644
--- a/Framework/DataHandling/src/LoadEventPreNexus2.cpp
+++ b/Framework/DataHandling/src/LoadEventPreNexus2.cpp
@@ -726,7 +726,7 @@ void LoadEventPreNexus2::procEvents(
   }
 
   // For slight speed up
-  loadOnlySomeSpectra = (this->spectra_list.size() > 0);
+  loadOnlySomeSpectra = (!this->spectra_list.empty());
 
   // Turn the spectra list into a map, for speed of access
   for (auto &spectrum : spectra_list)
diff --git a/Framework/DataHandling/src/LoadFullprofResolution.cpp b/Framework/DataHandling/src/LoadFullprofResolution.cpp
index df44aa49e105c573a719424551e8cf842196601c..494fd1aa2f98ebba834bce2efb5f1bf62bc51f65 100644
--- a/Framework/DataHandling/src/LoadFullprofResolution.cpp
+++ b/Framework/DataHandling/src/LoadFullprofResolution.cpp
@@ -138,7 +138,7 @@ void LoadFullprofResolution::exec() {
 
   if (vec_bankinirf.empty()) {
     throw runtime_error("No Bank is found in input file.");
-  } else if (outputbankids.size() == 0) {
+  } else if (outputbankids.empty()) {
     vec_bankids = vec_bankinirf;
     // If workspaces, set up Bank-Workpace correspondence
     if (wsg)
@@ -177,7 +177,7 @@ void LoadFullprofResolution::exec() {
         }
       }
     }
-    if (vec_bankids.size() == 0) {
+    if (vec_bankids.empty()) {
       g_log.error("There is no valid specified bank IDs for output.");
       throw runtime_error("There is no valid specified bank IDs for output.");
     }
@@ -208,7 +208,7 @@ void LoadFullprofResolution::exec() {
   if (wsg) {
     // First check that number of workspaces in group matches number of banks,
     // if no WorkspacesForBanks is specified.
-    if ((outputwsids.size() == 0) && (wsg->size() != vec_bankids.size())) {
+    if ((outputwsids.empty()) && (wsg->size() != vec_bankids.size())) {
       std::ostringstream mess;
       mess << "Number of banks (" << vec_bankids.size()
            << ") does not match number of workspaces (" << wsg->size()
@@ -786,7 +786,7 @@ TableWorkspace_sptr LoadFullprofResolution::genTableWorkspace(
 void LoadFullprofResolution::createBankToWorkspaceMap(
     const std::vector<int> &banks, const std::vector<int> &workspaces,
     std::map<int, size_t> &workspaceOfBank) {
-  if (workspaces.size() == 0) {
+  if (workspaces.empty()) {
     for (size_t i = 0; i < banks.size(); i++) {
       workspaceOfBank.emplace(banks[i], i + 1);
     }
diff --git a/Framework/DataHandling/src/LoadGSASInstrumentFile.cpp b/Framework/DataHandling/src/LoadGSASInstrumentFile.cpp
index 235a04af6879e2fa85de64857c9d9e1b72e59fb2..cd338e5bb07c6b6f64787097658a6b7954c88bf1 100644
--- a/Framework/DataHandling/src/LoadGSASInstrumentFile.cpp
+++ b/Framework/DataHandling/src/LoadGSASInstrumentFile.cpp
@@ -132,7 +132,7 @@ void LoadGSASInstrumentFile::exec() {
   vector<size_t> bankStartIndex;
   scanBanks(lines, bankStartIndex);
 
-  if (bankStartIndex.size() == 0) {
+  if (bankStartIndex.empty()) {
     throw std::runtime_error("No nanks found in file. \n");
   }
 
@@ -172,7 +172,7 @@ void LoadGSASInstrumentFile::exec() {
     map<int, size_t> workspaceOfBank;
 
     // Deal with bankIds
-    if (bankIds.size()) {
+    if (!bankIds.empty()) {
       // If user provided a list of banks, check that they exist in the .prm
       // file
       for (auto bankId : bankIds) {
diff --git a/Framework/DataHandling/src/LoadGSS.cpp b/Framework/DataHandling/src/LoadGSS.cpp
index 398b3a4719d62bfa9721fc0176029311abe6421e..87b92c443b6714c314cf5e6864f4f1aceef3b2ba 100644
--- a/Framework/DataHandling/src/LoadGSS.cpp
+++ b/Framework/DataHandling/src/LoadGSS.cpp
@@ -225,7 +225,7 @@ API::MatrixWorkspace_sptr LoadGSS::loadGSASFile(const std::string &filename,
 
       // If there is, Save the previous to array and initialze new MantiVec for
       // (X, Y, E)
-      if (vecX.size() != 0) {
+      if (!vecX.empty()) {
         std::vector<double> storeX = vecX;
         std::vector<double> storeY = vecY;
         std::vector<double> storeE = vecE;
@@ -297,7 +297,7 @@ API::MatrixWorkspace_sptr LoadGSS::loadGSASFile(const std::string &filename,
       double xPrev;
 
       // * Get previous X value
-      if (vecX.size() != 0) {
+      if (!vecX.empty()) {
         xPrev = vecX.back();
       } else if (filetype == 'r') {
         // Except if RALF
@@ -370,7 +370,7 @@ API::MatrixWorkspace_sptr LoadGSS::loadGSASFile(const std::string &filename,
   } // ENDWHILE of readling all lines
 
   // Push the vectors (X, Y, E) of the last bank to gsasData
-  if (vecX.size() != 0) { // Put final spectra into data
+  if (!vecX.empty()) { // Put final spectra into data
     gsasDataX.push_back(vecX);
     gsasDataY.push_back(vecY);
     gsasDataE.push_back(vecE);
diff --git a/Framework/DataHandling/src/LoadISISNexus2.cpp b/Framework/DataHandling/src/LoadISISNexus2.cpp
index a4f81bc5d9cc0c93b004db0438b38cd34d9d5f29..d2c762559d2c3ed2cf6c11f4742976106c3b2d62 100644
--- a/Framework/DataHandling/src/LoadISISNexus2.cpp
+++ b/Framework/DataHandling/src/LoadISISNexus2.cpp
@@ -538,7 +538,7 @@ void LoadISISNexus2::checkOptionalProperties(
       spec_list.erase(remove_if(spec_list.begin(), spec_list.end(), in_range),
                       spec_list.end());
       // combine spectra numbers from ranges and the list
-      if (spec_list.size() > 0) {
+      if (!spec_list.empty()) {
         for (int64_t i = spec_min; i < spec_max + 1; i++) {
           specnum_t spec_num = static_cast<specnum_t>(i);
           // remove excluded spectra now rather then inserting it here and
@@ -582,7 +582,7 @@ void LoadISISNexus2::buildSpectraInd2SpectraNumMap(
 
   int64_t ic(0);
 
-  if (spec_list.size() > 0) {
+  if (!spec_list.empty()) {
     ic = 0;
     auto start_point = spec_list.begin();
     for (auto it = start_point; it != spec_list.end(); it++) {
diff --git a/Framework/DataHandling/src/LoadMask.cpp b/Framework/DataHandling/src/LoadMask.cpp
index 0cd9cdf773fe63a58eabd5da37eafb0577913f24..d5e7d372e29818b30f6b629320183096d9258914 100644
--- a/Framework/DataHandling/src/LoadMask.cpp
+++ b/Framework/DataHandling/src/LoadMask.cpp
@@ -322,7 +322,7 @@ void LoadMask::processMaskOnWorkspaceIndex(bool mask,
                                            std::vector<int32_t> pairslow,
                                            std::vector<int32_t> pairsup) {
   // 1. Check
-  if (pairslow.size() == 0)
+  if (pairslow.empty())
     return;
   if (pairslow.size() != pairsup.size()) {
     g_log.error() << "Input spectrum IDs are not paired.  Size(low) = "
diff --git a/Framework/DataHandling/src/LoadNexusProcessed.cpp b/Framework/DataHandling/src/LoadNexusProcessed.cpp
index 6478a9366b1aa8961369d5ea79ba6e35f9c578d2..908bd8503a76aa3d66043136bcdd0dd8c0322b8b 100644
--- a/Framework/DataHandling/src/LoadNexusProcessed.cpp
+++ b/Framework/DataHandling/src/LoadNexusProcessed.cpp
@@ -2157,7 +2157,7 @@ LoadNexusProcessed::calculateWorkspaceSize(const std::size_t numberofspectra,
           } else
             ++it;
       }
-      if (m_spec_list.size() == 0)
+      if (m_spec_list.empty())
         m_list = false;
       total_specs += static_cast<int>(m_spec_list.size());
 
diff --git a/Framework/DataHandling/src/LoadPDFgetNFile.cpp b/Framework/DataHandling/src/LoadPDFgetNFile.cpp
index ab3b140f3a7edd635f49278b084e1aa2e9b44315..352742c26b5c334fb3d85c9556db2d3db413714c 100644
--- a/Framework/DataHandling/src/LoadPDFgetNFile.cpp
+++ b/Framework/DataHandling/src/LoadPDFgetNFile.cpp
@@ -309,7 +309,7 @@ void LoadPDFgetNFile::setUnit(Workspace2D_sptr ws) {
   */
 void LoadPDFgetNFile::generateDataWorkspace() {
   // 0. Check
-  if (mData.size() == 0) {
+  if (mData.empty()) {
     throw runtime_error("Data set has not been initialized. Quit!");
   }
 
diff --git a/Framework/DataHandling/src/LoadRawHelper.cpp b/Framework/DataHandling/src/LoadRawHelper.cpp
index f6353ffacb728cfb31ea859b7208e0704f7e8b88..fdd3a763d69a9efd6d28e8a4e3d1683fa5678256 100644
--- a/Framework/DataHandling/src/LoadRawHelper.cpp
+++ b/Framework/DataHandling/src/LoadRawHelper.cpp
@@ -918,7 +918,7 @@ void LoadRawHelper::checkOptionalProperties() {
   // Check validity of spectra list property, if set
   if (m_list) {
     m_list = true;
-    if (m_spec_list.size() == 0) {
+    if (m_spec_list.empty()) {
       m_list = false;
     } else {
       const int64_t minlist =
@@ -968,7 +968,7 @@ specnum_t LoadRawHelper::calculateWorkspaceSize() {
           } else
             ++it;
       }
-      if (m_spec_list.size() == 0)
+      if (m_spec_list.empty())
         m_list = false;
       total_specs += static_cast<specnum_t>(m_spec_list.size());
       m_total_specs = total_specs;
@@ -1025,7 +1025,7 @@ void LoadRawHelper::calculateWorkspacesizes(
           else
             ++itr;
         }
-        if (m_spec_list.size() == 0) {
+        if (m_spec_list.empty()) {
           g_log.debug() << "normalwsSpecs is " << normalwsSpecs
                         << "  monitorwsSpecs is " << monitorwsSpecs
                         << std::endl;
diff --git a/Framework/DataHandling/src/LoadReflTBL.cpp b/Framework/DataHandling/src/LoadReflTBL.cpp
index b47e3b6e765350e11ea443e2cc2d93df3a75ddb8..14ad0864ebde410cd45fa2754416e49ca28fe0e8 100644
--- a/Framework/DataHandling/src/LoadReflTBL.cpp
+++ b/Framework/DataHandling/src/LoadReflTBL.cpp
@@ -208,7 +208,7 @@ size_t LoadReflTBL::getCells(std::string line,
     findQuotePairs(line, quoteBounds);
     // if we didn't find any quotes, then there are too many commas and we
     // definitely have too many delimiters
-    if (quoteBounds.size() == 0) {
+    if (quoteBounds.empty()) {
       std::string message =
           "A line must contain 16 cell-delimiting commas. Found " +
           boost::lexical_cast<std::string>(found) + ".";
diff --git a/Framework/DataHandling/src/LoadSassena.cpp b/Framework/DataHandling/src/LoadSassena.cpp
index 3ae179ed558f93f70f7fbdea9def8cd08303e2a6..dbc73f02eea143ec8303b5b0e4d404272abb686d 100644
--- a/Framework/DataHandling/src/LoadSassena.cpp
+++ b/Framework/DataHandling/src/LoadSassena.cpp
@@ -412,7 +412,7 @@ void LoadSassena::exec() {
   // Block to read the Q-vectors
   std::vector<int> sorting_indexes;
   const MantidVec qvmod = this->loadQvectors(h5file, gws, sorting_indexes);
-  if (qvmod.size() == 0) {
+  if (qvmod.empty()) {
     this->g_log.error("No Q-vectors read. Unable to proceed");
     H5Fclose(h5file);
     return;
diff --git a/Framework/DataHandling/src/LoadSpiceAscii.cpp b/Framework/DataHandling/src/LoadSpiceAscii.cpp
index 30828e22b09bc33e48a000e63e7970c5e1e483c6..8fa1adba9891028fe539fd703acf3aee5d22d490 100644
--- a/Framework/DataHandling/src/LoadSpiceAscii.cpp
+++ b/Framework/DataHandling/src/LoadSpiceAscii.cpp
@@ -445,7 +445,7 @@ void LoadSpiceAscii::setupRunStartTime(
     API::MatrixWorkspace_sptr runinfows,
     const std::vector<std::string> &datetimeprop) {
   // Check if no need to process run start time
-  if (datetimeprop.size() == 0) {
+  if (datetimeprop.empty()) {
     g_log.information("User chooses not to set up run start date and time.");
     return;
   }
diff --git a/Framework/DataHandling/src/SaveNXTomo.cpp b/Framework/DataHandling/src/SaveNXTomo.cpp
index 654e5fa5992afe6ecd661586abc9db94bd1ecd53..61bdad87d6b7f252c3d42f4e5ee431c9bad5cacc 100644
--- a/Framework/DataHandling/src/SaveNXTomo.cpp
+++ b/Framework/DataHandling/src/SaveNXTomo.cpp
@@ -76,7 +76,7 @@ void SaveNXTomo::exec() {
   } catch (...) {
   }
 
-  if (m_workspaces.size() != 0)
+  if (!m_workspaces.empty())
     processAll();
 }
 
@@ -96,7 +96,7 @@ bool SaveNXTomo::processGroups() {
   } catch (...) {
   }
 
-  if (m_workspaces.size() != 0)
+  if (!m_workspaces.empty())
     processAll();
 
   return true;
diff --git a/Framework/DataObjects/inc/MantidDataObjects/MDBox.tcc b/Framework/DataObjects/inc/MantidDataObjects/MDBox.tcc
index 2fdd4adf66c73f3e092b96c3c900c555c1f2ed0f..100e9e91fb3fb506f41e4dfb1005cf25b935685f 100644
--- a/Framework/DataObjects/inc/MantidDataObjects/MDBox.tcc
+++ b/Framework/DataObjects/inc/MantidDataObjects/MDBox.tcc
@@ -378,7 +378,7 @@ TMDE(bool MDBox)::isDataAdded() const {
     if (m_Saveable->isLoaded())
       return data.size() != m_Saveable->getFileSize();
   }
-  return (data.size() != 0);
+  return (!data.empty());
 }
 
 //-----------------------------------------------------------------------------------------------
diff --git a/Framework/DataObjects/src/EventList.cpp b/Framework/DataObjects/src/EventList.cpp
index f2a38dbd89a7abf74a21c09b67f759679d0e2651..5f9f4b52247115229d4e5f1361ad188609b9f2de 100644
--- a/Framework/DataObjects/src/EventList.cpp
+++ b/Framework/DataObjects/src/EventList.cpp
@@ -1973,7 +1973,7 @@ void EventList::histogramForWeightsHelper(const std::vector<T> &events,
   //---------------------------------
 
   // Do we even have any events to do?
-  if (events.size() > 0) {
+  if (!events.empty()) {
     // Iterate through all events (sorted by tof)
     auto itev = findFirstEvent(events, X[0]);
     auto itev_end = events.cend();
@@ -2167,7 +2167,7 @@ void EventList::generateCountsHistogramPulseTime(const MantidVec &X,
   //---------------------- Histogram without weights
   //---------------------------------
 
-  if (this->events.size() > 0) {
+  if (!this->events.empty()) {
     // Iterate through all events (sorted by pulse time)
     auto itev = findFirstPulseEvent(this->events, X[0]);
     auto itev_end = events.cend(); // cache for speed
@@ -2239,7 +2239,7 @@ void EventList::generateCountsHistogramTimeAtSample(
   //---------------------- Histogram without weights
   //---------------------------------
 
-  if (this->events.size() > 0) {
+  if (!this->events.empty()) {
     // Iterate through all events (sorted by pulse time)
     auto itev =
         findFirstTimeAtSampleEvent(this->events, X[0], tofFactor, tofOffset);
@@ -2311,7 +2311,7 @@ void EventList::generateCountsHistogram(const MantidVec &X,
   //---------------------------------
 
   // Do we even have any events to do?
-  if (this->events.size() > 0) {
+  if (!this->events.empty()) {
     // Iterate through all events (sorted by tof)
     std::vector<TofEvent>::const_iterator itev =
         findFirstEvent(this->events, X[0]);
@@ -2407,7 +2407,7 @@ void EventList::integrateHelper(std::vector<T> &events, const double minX,
   sum = 0;
   error = 0;
   // Nothing in the list?
-  if (events.size() == 0)
+  if (events.empty())
     return;
 
   // Iterators for limits - whole range by default
@@ -3986,7 +3986,7 @@ void EventList::splitByTime(Kernel::TimeSplitterType &splitter,
   }
 
   // Do nothing if there are no entries
-  if (splitter.size() <= 0)
+  if (splitter.empty())
     return;
 
   switch (eventType) {
@@ -4131,7 +4131,7 @@ void EventList::splitByFullTime(Kernel::TimeSplitterType &splitter,
   }
 
   // Do nothing if there are no entries
-  if (splitter.size() <= 0) {
+  if (splitter.empty()) {
     // 3A. Copy all events to group workspace = -1
     (*outputs[-1]) = (*this);
     // this->duplicate(outputs[-1]);
@@ -4263,7 +4263,7 @@ std::string EventList::splitByFullTimeMatrixSplitter(
   std::string debugmessage("");
 
   // Do nothing if there are no entries
-  if (vecgroups.size() == 0) {
+  if (vecgroups.empty()) {
     // Copy all events to group workspace = -1
     (*vec_outputEventList[-1]) = (*this);
     // this->duplicate(outputs[-1]);
@@ -4383,7 +4383,7 @@ void EventList::splitByPulseTime(Kernel::TimeSplitterType &splitter,
   }
 
   // Split
-  if (splitter.size() <= 0) {
+  if (splitter.empty()) {
     // No splitter: copy all events to group workspace = -1
     (*outputs[-1]) = (*this);
   } else {
diff --git a/Framework/DataObjects/src/Workspace2D.cpp b/Framework/DataObjects/src/Workspace2D.cpp
index dfb94df00cff3328794ff3ce141203d6bedfe0d5..b3acd6688f27137ef34e2cf229b556f660f06571 100644
--- a/Framework/DataObjects/src/Workspace2D.cpp
+++ b/Framework/DataObjects/src/Workspace2D.cpp
@@ -107,7 +107,7 @@ size_t Workspace2D::size() const { return data.size() * blocksize(); }
 
 /// get the size of each vector
 size_t Workspace2D::blocksize() const {
-  return (data.size() > 0)
+  return (!data.empty())
              ? static_cast<ISpectrum const *>(data[0])->dataY().size()
              : 0;
 }
diff --git a/Framework/Geometry/src/ComponentParser.cpp b/Framework/Geometry/src/ComponentParser.cpp
index 53b5c12d9d9aa0f67deda7ed435451e1dfec5b41..a912cd0ffe2755a6dfcff8df45c943b054d25499 100644
--- a/Framework/Geometry/src/ComponentParser.cpp
+++ b/Framework/Geometry/src/ComponentParser.cpp
@@ -7,7 +7,7 @@ namespace Geometry {
 
 /** @return the top-level component created */
 Component *ComponentParser::getComponent() {
-  if (m_current.size() > 0)
+  if (!m_current.empty())
     return m_current[0];
   else
     return nullptr;
diff --git a/Framework/Geometry/src/Crystal/Group.cpp b/Framework/Geometry/src/Crystal/Group.cpp
index f89540d6adbe763109d27bbe8ad90a7278c87f62..bf00f72c866df3c7b357c9d201858f6b1ddd9233 100644
--- a/Framework/Geometry/src/Crystal/Group.cpp
+++ b/Framework/Geometry/src/Crystal/Group.cpp
@@ -128,7 +128,7 @@ bool Group::isGroup() const {
 /// empty.
 void Group::setSymmetryOperations(
     const std::vector<SymmetryOperation> &symmetryOperations) {
-  if (symmetryOperations.size() < 1) {
+  if (symmetryOperations.empty()) {
     throw std::invalid_argument("Group needs at least one element.");
   }
 
diff --git a/Framework/Geometry/src/Crystal/IndexingUtils.cpp b/Framework/Geometry/src/Crystal/IndexingUtils.cpp
index 5e231dc844a14267b6ac2a4c4534f0642039155c..780d3a09188932eb107a3c48eeefdd46dfd41aba 100644
--- a/Framework/Geometry/src/Crystal/IndexingUtils.cpp
+++ b/Framework/Geometry/src/Crystal/IndexingUtils.cpp
@@ -1925,7 +1925,7 @@ double IndexingUtils::IndexingError(const DblMatrix &UB,
     total_error += h_error + k_error + l_error;
   }
 
-  if (hkls.size() > 0)
+  if (!hkls.empty())
     return total_error / (3.0 * static_cast<double>(hkls.size()));
   else
     return 0;
@@ -2522,11 +2522,11 @@ int IndexingUtils::SelectDirection(V3D &best_direction,
                                    const std::vector<V3D> direction_list,
                                    double plane_spacing,
                                    double required_tolerance) {
-  if (q_vectors.size() == 0) {
+  if (q_vectors.empty()) {
     throw std::invalid_argument("SelectDirection(): No Q vectors specified");
   }
 
-  if (direction_list.size() == 0) {
+  if (direction_list.empty()) {
     throw std::invalid_argument(
         "SelectDirection(): List of possible directions has zero length");
   }
diff --git a/Framework/Geometry/src/Crystal/ScalarUtils.cpp b/Framework/Geometry/src/Crystal/ScalarUtils.cpp
index 32a3e80f1db0aa094e482cbc70bcc4895c58df0b..dd9cc6a17fa4fc74462e37d8bb4a2375112ebccf 100644
--- a/Framework/Geometry/src/Crystal/ScalarUtils.cpp
+++ b/Framework/Geometry/src/Crystal/ScalarUtils.cpp
@@ -263,7 +263,7 @@ ConventionalCell ScalarUtils::GetCellForForm(const DblMatrix &UB,
  */
 void ScalarUtils::RemoveHighErrorForms(std::vector<ConventionalCell> &list,
                                        double level) {
-  if (list.size() <= 0) // nothing to do
+  if (list.empty()) // nothing to do
     return;
 
   std::vector<ConventionalCell> new_list;
@@ -293,7 +293,7 @@ void ScalarUtils::RemoveHighErrorForms(std::vector<ConventionalCell> &list,
 ConventionalCell
 ScalarUtils::GetCellBestError(const std::vector<ConventionalCell> &list,
                               bool use_triclinic) {
-  if (list.size() == 0) {
+  if (list.empty()) {
     throw std::invalid_argument("GetCellBestError(): list is empty");
   }
 
diff --git a/Framework/Geometry/src/Instrument/Goniometer.cpp b/Framework/Geometry/src/Instrument/Goniometer.cpp
index 4bc05a186f9677db2a47b8d4145a34ae03d0131c..4b50fe05e788a53e7d19642df5e9046db3f6fc2d 100644
--- a/Framework/Geometry/src/Instrument/Goniometer.cpp
+++ b/Framework/Geometry/src/Instrument/Goniometer.cpp
@@ -90,7 +90,7 @@ std::string Goniometer::axesInfo() {
     std::vector<GoniometerAxis>::iterator it;
     std::string strCW("CW"), strCCW("CCW"), sense;
 
-    if (motors.size() == 0) {
+    if (motors.empty()) {
       info << "No axis is found\n";
     } else {
       info << "Name \t Direction \t Sense \t Angle \n";
diff --git a/Framework/Geometry/src/Instrument/InstrumentDefinitionParser.cpp b/Framework/Geometry/src/Instrument/InstrumentDefinitionParser.cpp
index 02baf75e2d014771c5189154d82a4dab84fcf49a..84e7d5a71ce6fffba2a7011061b7710a73b8f1da 100644
--- a/Framework/Geometry/src/Instrument/InstrumentDefinitionParser.cpp
+++ b/Framework/Geometry/src/Instrument/InstrumentDefinitionParser.cpp
@@ -417,7 +417,7 @@ InstrumentDefinitionParser::parseXML(Kernel::ProgressBase *prog) {
         if (!pElem->hasAttribute("idlist")) {
           g_log.error("No detector ID list found for detectors of type " +
                       pElem->getAttribute("type"));
-        } else if (idList.vec.size() == 0) {
+        } else if (idList.vec.empty()) {
           g_log.error("No detector IDs found for detectors in list " +
                       pElem->getAttribute("idlist") + "for detectors of type" +
                       pElem->getAttribute("type"));
@@ -1339,7 +1339,7 @@ void InstrumentDefinitionParser::appendLeaf(Geometry::ICompAssembly *parent,
                     name);
         throw Kernel::Exception::InstrumentDefinitionError(
             "Detector location element " + name + " has no idlist.", filename);
-      } else if (idList.vec.size() == 0) {
+      } else if (idList.vec.empty()) {
         g_log.error("No detector IDs found for detectors in list " +
                     idList.idname);
       } else {
diff --git a/Framework/Geometry/src/MDGeometry/MDImplicitFunction.cpp b/Framework/Geometry/src/MDGeometry/MDImplicitFunction.cpp
index 56c538a79e67a8b82c0cd293ddf0aab55ce1daff..fd10bcc6045f70f038f64d81701536187c71a72a 100644
--- a/Framework/Geometry/src/MDGeometry/MDImplicitFunction.cpp
+++ b/Framework/Geometry/src/MDGeometry/MDImplicitFunction.cpp
@@ -16,7 +16,7 @@ MDImplicitFunction::MDImplicitFunction() : m_nd(0), m_numPlanes(0) {}
  */
 void MDImplicitFunction::addPlane(const MDPlane &plane) {
   // Number of dimensions must match
-  if (m_planes.size() > 0) {
+  if (!m_planes.empty()) {
     if (m_nd != plane.getNumDims())
       throw std::invalid_argument("MDImplicitFunction::addPlane(): cannot add "
                                   "a plane with different number of dimensions "
diff --git a/Framework/Geometry/src/Math/Acomp.cpp b/Framework/Geometry/src/Math/Acomp.cpp
index 8db58e30ed1f403c719edb0d914f6c52010ee96d..53472e2e0c45614dc337005d27156dfc78da6de4 100644
--- a/Framework/Geometry/src/Math/Acomp.cpp
+++ b/Framework/Geometry/src/Math/Acomp.cpp
@@ -536,7 +536,7 @@ A. This will make the form DNF.
 {
   Units.clear();
   deleteComp();
-  if (A.size() == 0)
+  if (A.empty())
     return;
 
   if (A.size() == 1) // special case for single intersection
@@ -566,7 +566,7 @@ A. This will make the form DNF.
 {
   Units.clear();
   deleteComp();
-  if (A.size() == 0)
+  if (A.empty())
     return;
 
   if (A.size() == 1) // special case for single union
@@ -663,7 +663,7 @@ int Acomp::isNull() const
 @return 1 if there are no memebers
 */
 {
-  return ((!Units.size() && !Comp.size()) ? 1 : 0);
+  return ((Units.empty() && Comp.empty()) ? 1 : 0);
 }
 
 int Acomp::isDNF() const
@@ -888,7 +888,7 @@ It is set on exit (to the EPI)
 */
 {
   const int debug(0);
-  if (!PIform.size())
+  if (PIform.empty())
     return 0;
 
   std::vector<BnId> EPI; // Created Here.
@@ -1358,7 +1358,7 @@ singles exist and up-promotes them.
     const Acomp *Lower = itemC(0); // returns pointer
     Units.clear();
     Intersect = Lower->Intersect;
-    if (Lower->Units.size()) {
+    if (!Lower->Units.empty()) {
       Units.resize(Lower->Units.size());
       copy(Lower->Units.begin(), Lower->Units.end(), Units.begin());
     }
diff --git a/Framework/Kernel/inc/MantidKernel/Interpolation.h b/Framework/Kernel/inc/MantidKernel/Interpolation.h
index bf837df3312bf2ce1135fd6ee4af6c4eafb1f23b..623ac263ee6ed5dc8c306fd566e3c22b95afa42d 100644
--- a/Framework/Kernel/inc/MantidKernel/Interpolation.h
+++ b/Framework/Kernel/inc/MantidKernel/Interpolation.h
@@ -94,7 +94,7 @@ public:
   Unit_sptr getYUnit() const { return m_yUnit; };
 
   /// return false if no data has been added
-  bool containData() const { return m_x.size() ? true : false; }
+  bool containData() const { return !m_x.empty() ? true : false; }
 
   /// Prints object to stream
   void printSelf(std::ostream &os) const;
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h b/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
index f093f4b73d39582cada447d7713e18682f21bf4b..e648178413919a3876bb3328ff5b30d41980bdff 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadScheduler.h
@@ -169,7 +169,7 @@ public:
     m_queueLock.lock();
     // Check the size within the same locking block; otherwise the size may
     // change before you get the next item.
-    if (m_queue.size() > 0) {
+    if (!m_queue.empty()) {
       // TODO: Would a try/catch block be smart here?
       temp = m_queue.front();
       m_queue.pop_front();
@@ -222,7 +222,7 @@ class MANTID_KERNEL_DLL ThreadSchedulerLIFO : public ThreadSchedulerFIFO {
     m_queueLock.lock();
     // Check the size within the same locking block; otherwise the size may
     // change before you get the next item.
-    if (m_queue.size() > 0) {
+    if (!m_queue.empty()) {
       // TODO: Would a try/catch block be smart here?
       temp = m_queue.back();
       m_queue.pop_back();
@@ -274,7 +274,7 @@ public:
     m_queueLock.lock();
     // Check the size within the same locking block; otherwise the size may
     // change before you get the next item.
-    if (m_map.size() > 0) {
+    if (!m_map.empty()) {
       // Since the map is sorted by cost, we want the LAST item.
       std::multimap<double, Task *>::iterator it = m_map.end();
       it--;
diff --git a/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h b/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
index 11cbe60535c1ff4fa093298bd3dbed47b9464922..ca960fe8b4b8700f1485a8c546437fb59798af99 100644
--- a/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
+++ b/Framework/Kernel/inc/MantidKernel/ThreadSchedulerMutexes.h
@@ -50,7 +50,7 @@ public:
     std::lock_guard<std::mutex> lock(m_queueLock);
     // Check the size within the same locking block; otherwise the size may
     // change before you get the next item.
-    if (m_supermap.size() > 0) {
+    if (!m_supermap.empty()) {
       // We iterate in reverse as to take the NULL mutex last, even if no mutex
       // is busy
       SuperMap::iterator it = m_supermap.begin();
@@ -63,7 +63,7 @@ public:
           // The mutex of this map is free!
           InnerMap &map = it->second;
 
-          if (map.size() > 0) {
+          if (!map.empty()) {
             // Look for the largest cost item in it.
             InnerMap::iterator it2 = it->second.end();
             it2--;
@@ -81,7 +81,7 @@ public:
         SuperMap::iterator it = m_supermap.begin();
         SuperMap::iterator it_end = m_supermap.end();
         for (; it != it_end; it++) {
-          if (it->second.size() > 0) {
+          if (!it->second.empty()) {
             InnerMap &map = it->second;
             // Use the first one
             temp = map.begin()->second;
diff --git a/Framework/Kernel/src/BinFinder.cpp b/Framework/Kernel/src/BinFinder.cpp
index e73310b8c537daef3240482761a23c1b0cf03456..4cba89b83f84988ab7e3953edbdfaf4dcfd2894c 100644
--- a/Framework/Kernel/src/BinFinder.cpp
+++ b/Framework/Kernel/src/BinFinder.cpp
@@ -98,7 +98,7 @@ BinFinder::BinFinder(const std::vector<double> &binParams) {
  * which should be == to the size of the X axis.
  */
 int BinFinder::lastBinIndex() {
-  if (endBinIndex.size() > 0)
+  if (!endBinIndex.empty())
     return endBinIndex[endBinIndex.size() - 1];
   else
     return -1;
diff --git a/Framework/Kernel/src/RemoteJobManager.cpp b/Framework/Kernel/src/RemoteJobManager.cpp
index d0e8c6b9c1e31cd2dc19aeafa25b009679aba599..084e4c3b0f52ec486d082014ec91f538d0508b87 100644
--- a/Framework/Kernel/src/RemoteJobManager.cpp
+++ b/Framework/Kernel/src/RemoteJobManager.cpp
@@ -79,7 +79,7 @@ std::istream &RemoteJobManager::httpGet(const std::string &path,
   // session cookie.
   std::vector<Poco::Net::HTTPCookie> newCookies;
   m_response.getCookies(newCookies);
-  if (newCookies.size() > 0) {
+  if (!newCookies.empty()) {
     m_cookies = newCookies;
   }
 
@@ -168,7 +168,7 @@ std::istream &RemoteJobManager::httpPost(const std::string &path,
   // session cookie.
   std::vector<Poco::Net::HTTPCookie> newCookies;
   m_response.getCookies(newCookies);
-  if (newCookies.size() > 0) {
+  if (!newCookies.empty()) {
     m_cookies = newCookies;
   }
 
diff --git a/Framework/Kernel/src/Statistics.cpp b/Framework/Kernel/src/Statistics.cpp
index 7c5909edf757c4aac1f8c3b183bed1bc9de33248..c7d3d11d480545a92b46c0cb5b0b447042aa2380 100644
--- a/Framework/Kernel/src/Statistics.cpp
+++ b/Framework/Kernel/src/Statistics.cpp
@@ -232,7 +232,7 @@ Rfactor getRFactor(const std::vector<double> &obsI,
           << ") have different number of elements.";
     throw std::runtime_error(errss.str());
   }
-  if (obsI.size() == 0) {
+  if (obsI.empty()) {
     throw std::runtime_error("getRFactor(): the input arrays are empty.");
   }
 
diff --git a/Framework/Kernel/src/TimeSeriesProperty.cpp b/Framework/Kernel/src/TimeSeriesProperty.cpp
index d806dc1a132e75d8e27cf2f165412afac44f30a5..a90c6aac521c0374e280834a47a0fb141e11bf60 100644
--- a/Framework/Kernel/src/TimeSeriesProperty.cpp
+++ b/Framework/Kernel/src/TimeSeriesProperty.cpp
@@ -824,7 +824,7 @@ TimeSeriesProperty<TYPE>::valueAsCorrectMap() const {
   // 2. Data Strcture
   std::map<DateAndTime, TYPE> asMap;
 
-  if (m_values.size() > 0) {
+  if (!m_values.empty()) {
     for (size_t i = 0; i < m_values.size(); i++)
       asMap[m_values[i].time()] = m_values[i].value();
   }
@@ -860,7 +860,7 @@ std::multimap<DateAndTime, TYPE>
 TimeSeriesProperty<TYPE>::valueAsMultiMap() const {
   std::multimap<DateAndTime, TYPE> asMultiMap;
 
-  if (m_values.size() > 0) {
+  if (!m_values.empty()) {
     for (size_t i = 0; i < m_values.size(); i++)
       asMultiMap.insert(
           std::make_pair(m_values[i].time(), m_values[i].value()));
@@ -987,7 +987,7 @@ void TimeSeriesProperty<TYPE>::addValues(
     }
   }
 
-  if (values.size() > 0)
+  if (!values.empty())
     m_propSortedFlag = TimeSeriesSortStatus::TSUNKNOWN;
 
   return;
@@ -1012,7 +1012,7 @@ void TimeSeriesProperty<TYPE>::replaceValues(
  */
 template <typename TYPE>
 DateAndTime TimeSeriesProperty<TYPE>::lastTime() const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("lastTime(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1028,7 +1028,7 @@ DateAndTime TimeSeriesProperty<TYPE>::lastTime() const {
  *  @return Value
  */
 template <typename TYPE> TYPE TimeSeriesProperty<TYPE>::firstValue() const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("firstValue(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1045,7 +1045,7 @@ template <typename TYPE> TYPE TimeSeriesProperty<TYPE>::firstValue() const {
  */
 template <typename TYPE>
 DateAndTime TimeSeriesProperty<TYPE>::firstTime() const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("firstTime(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1062,7 +1062,7 @@ DateAndTime TimeSeriesProperty<TYPE>::firstTime() const {
  *  @return Value
  */
 template <typename TYPE> TYPE TimeSeriesProperty<TYPE>::lastValue() const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("lastValue(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1156,7 +1156,7 @@ std::map<DateAndTime, TYPE> TimeSeriesProperty<TYPE>::valueAsMap() const {
   // 2. Build map
 
   std::map<DateAndTime, TYPE> asMap;
-  if (m_values.size() == 0)
+  if (m_values.empty())
     return asMap;
 
   TYPE d = m_values[0].value();
@@ -1288,7 +1288,7 @@ void TimeSeriesProperty<TYPE>::create(const std::vector<DateAndTime> &new_times,
  */
 template <typename TYPE>
 TYPE TimeSeriesProperty<TYPE>::getSingleValue(const DateAndTime &t) const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("getSingleValue(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1337,7 +1337,7 @@ TYPE TimeSeriesProperty<TYPE>::getSingleValue(const DateAndTime &t) const {
 template <typename TYPE>
 TYPE TimeSeriesProperty<TYPE>::getSingleValue(const DateAndTime &t,
                                               int &index) const {
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("getSingleValue(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1393,7 +1393,7 @@ TYPE TimeSeriesProperty<TYPE>::getSingleValue(const DateAndTime &t,
 template <typename TYPE>
 TimeInterval TimeSeriesProperty<TYPE>::nthInterval(int n) const {
   // 0. Throw exception
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("nthInterval(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1407,7 +1407,7 @@ TimeInterval TimeSeriesProperty<TYPE>::nthInterval(int n) const {
 
   Kernel::TimeInterval deltaT;
 
-  if (m_filter.size() == 0) {
+  if (m_filter.empty()) {
     // I. No filter
     if (n >= static_cast<int>(m_values.size()) ||
         (n == static_cast<int>(m_values.size()) - 1 && m_values.size() == 1)) {
@@ -1512,7 +1512,7 @@ template <typename TYPE> TYPE TimeSeriesProperty<TYPE>::nthValue(int n) const {
   TYPE value;
 
   // 1. Throw error if property is empty
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("nthValue(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1522,7 +1522,7 @@ template <typename TYPE> TYPE TimeSeriesProperty<TYPE>::nthValue(int n) const {
   // 2. Sort and apply filter
   sort();
 
-  if (m_filter.size() == 0) {
+  if (m_filter.empty()) {
     // 3. Situation 1:  No filter
     if (static_cast<size_t>(n) < m_values.size()) {
       TimeValueUnit<TYPE> entry = m_values[static_cast<std::size_t>(n)];
@@ -1568,7 +1568,7 @@ template <typename TYPE>
 Kernel::DateAndTime TimeSeriesProperty<TYPE>::nthTime(int n) const {
   sort();
 
-  if (m_values.size() == 0) {
+  if (m_values.empty()) {
     const std::string error("nthTime(): TimeSeriesProperty '" + name() +
                             "' is empty");
     g_log.debug(error);
@@ -1683,7 +1683,7 @@ template <typename TYPE> void TimeSeriesProperty<TYPE>::clearFilter() {
  * Updates size()
  */
 template <typename TYPE> void TimeSeriesProperty<TYPE>::countSize() const {
-  if (m_filter.size() == 0) {
+  if (m_filter.empty()) {
     // 1. Not filter
     m_size = int(m_values.size());
   } else {
@@ -1883,7 +1883,7 @@ template <typename TYPE> void TimeSeriesProperty<TYPE>::sort() const {
 template <typename TYPE>
 int TimeSeriesProperty<TYPE>::findIndex(Kernel::DateAndTime t) const {
   // 0. Return with an empty container
-  if (m_values.size() == 0)
+  if (m_values.empty())
     return 0;
 
   // 1. Sort
@@ -1965,7 +1965,7 @@ template <typename TYPE> void TimeSeriesProperty<TYPE>::applyFilter() const {
   // 1. Check and reset
   if (m_filterApplied)
     return;
-  if (m_filter.size() == 0)
+  if (m_filter.empty())
     return;
 
   m_filterQuickRef.clear();
@@ -1985,7 +1985,7 @@ template <typename TYPE> void TimeSeriesProperty<TYPE>::applyFilter() const {
 
       if (icurlog < 0) {
         // i. If it is out of lower boundary, add filter time, add 0 time
-        if (m_filterQuickRef.size() > 0)
+        if (!m_filterQuickRef.empty())
           throw std::logic_error(
               "return log index < 0 only occurs with the first log entry");
 
@@ -2004,7 +2004,7 @@ template <typename TYPE> void TimeSeriesProperty<TYPE>::applyFilter() const {
       } else {
         // iii. The returned value is in the boundary.
         size_t numintervals = 0;
-        if (m_filterQuickRef.size() > 0) {
+        if (!m_filterQuickRef.empty()) {
           numintervals = m_filterQuickRef.back().second;
         }
         if (m_filter[ift].first <
@@ -2084,7 +2084,7 @@ size_t TimeSeriesProperty<TYPE>::findNthIndexFromQuickRef(int n) const {
   // 1. Do check
   if (n < 0)
     throw std::invalid_argument("Unable to take into account negative index. ");
-  else if (m_filterQuickRef.size() == 0)
+  else if (m_filterQuickRef.empty())
     throw std::runtime_error("Quick reference is not established. ");
 
   // 2. Return...
diff --git a/Framework/Kernel/src/TimeSplitter.cpp b/Framework/Kernel/src/TimeSplitter.cpp
index c013801c7c3233b8dff2d2e67415c6073552c90e..82d9dd3c4e86f044833be93608963dadc6089964 100644
--- a/Framework/Kernel/src/TimeSplitter.cpp
+++ b/Framework/Kernel/src/TimeSplitter.cpp
@@ -139,7 +139,7 @@ TimeSplitterType operator&(const TimeSplitterType &a,
   TimeSplitterType out;
   // If either is empty, then no entries in the filter (aka everything is
   // removed)
-  if ((a.size() == 0) || (b.size() == 0))
+  if ((a.empty()) || (b.empty()))
     return out;
 
   TimeSplitterType::const_iterator ait;
@@ -241,7 +241,7 @@ TimeSplitterType operator~(const TimeSplitterType &a) {
   temp = removeFilterOverlap(a);
 
   // No entries: then make a "filter" that keeps everything
-  if ((temp.size() == 0)) {
+  if ((temp.empty())) {
     out.push_back(
         SplittingInterval(DateAndTime::minimum(), DateAndTime::maximum(), 0));
     return out;
diff --git a/Framework/Kernel/src/VMD.cpp b/Framework/Kernel/src/VMD.cpp
index 59bfe4a12a2153685dc36509edb027bd07ec46f0..18f55ed21339e43cc4818aa8b4c4ce93113ff506 100644
--- a/Framework/Kernel/src/VMD.cpp
+++ b/Framework/Kernel/src/VMD.cpp
@@ -81,7 +81,7 @@ VMDBase<TYPE>::makeVectorsOrthogonal(std::vector<VMDBase> &vectors) {
 template <typename TYPE>
 VMDBase<TYPE>
 VMDBase<TYPE>::getNormalVector(const std::vector<VMDBase<TYPE>> &vectors) {
-  if (vectors.size() <= 0)
+  if (vectors.empty())
     throw std::invalid_argument(
         "VMDBase::getNormalVector: Must give at least 1 vector");
   size_t nd = vectors[0].getNumDims();
diff --git a/Framework/MDAlgorithms/src/ConvertCWPDMDToSpectra.cpp b/Framework/MDAlgorithms/src/ConvertCWPDMDToSpectra.cpp
index 3acf7916ffa36667f2062143e6dec444cb322899..7b149c33616dc87044d3f88564870801bb62c01a 100644
--- a/Framework/MDAlgorithms/src/ConvertCWPDMDToSpectra.cpp
+++ b/Framework/MDAlgorithms/src/ConvertCWPDMDToSpectra.cpp
@@ -361,7 +361,7 @@ void ConvertCWPDMDToSpectra::findXBoundary(
     // Get source and sample position
     std::vector<detid_t> vec_detid =
         dataws->getExperimentInfo(irun)->getInstrument()->getDetectorIDs(true);
-    if (vec_detid.size() == 0) {
+    if (vec_detid.empty()) {
       g_log.information() << "Run " << runnumber << " has no detectors."
                           << "\n";
       continue;
diff --git a/Framework/MDAlgorithms/src/ConvertSpiceDataToRealSpace.cpp b/Framework/MDAlgorithms/src/ConvertSpiceDataToRealSpace.cpp
index 91c6950333c94c8a13aa3de83f6e824632c203ef..6349036e109ec263fed9ba3bf97bd80da6775642 100644
--- a/Framework/MDAlgorithms/src/ConvertSpiceDataToRealSpace.cpp
+++ b/Framework/MDAlgorithms/src/ConvertSpiceDataToRealSpace.cpp
@@ -411,7 +411,7 @@ void ConvertSpiceDataToRealSpace::readTableInfo(
   } // ENDFOR (icol)
 
   // Check detectors' names
-  if (anodelist.size() == 0) {
+  if (anodelist.empty()) {
     std::stringstream errss;
     errss << "There is no log name starting with " << anodelogprefix
           << " for detector. ";
diff --git a/Framework/MDAlgorithms/src/Integrate3DEvents.cpp b/Framework/MDAlgorithms/src/Integrate3DEvents.cpp
index 4b5623d8109d96dd494579bf71eeaa64ea80b04e..14be5bb98b524686ee132508f01460c26387977d 100644
--- a/Framework/MDAlgorithms/src/Integrate3DEvents.cpp
+++ b/Framework/MDAlgorithms/src/Integrate3DEvents.cpp
@@ -529,7 +529,7 @@ PeakShapeEllipsoid_const_sptr Integrate3DEvents::ellipseIntegrateEvents(
     axes_radii.push_back(r1 * sigmas[i]);
   }
 
-  if (E1Vec.size() > 0) {
+  if (!E1Vec.empty()) {
     double h3 = 1.0 - detectorQ(E1Vec, peak_q, abcBackgroundOuterRadii);
     // scaled from area of circle minus segment when r normalized to 1
     double m3 = std::sqrt(
diff --git a/Framework/MDAlgorithms/src/LoadILLAscii.cpp b/Framework/MDAlgorithms/src/LoadILLAscii.cpp
index a0c08fd14cb40a04989cec3039e51a58c0f4653d..908e22a5c2dc9e29fb2b063a79e84e953346f543 100644
--- a/Framework/MDAlgorithms/src/LoadILLAscii.cpp
+++ b/Framework/MDAlgorithms/src/LoadILLAscii.cpp
@@ -295,7 +295,7 @@ IMDEventWorkspace_sptr LoadILLAscii::mergeWorkspaces(
             "coords" << std::endl;
   myfile << "MDEVENTS" << std::endl;
 
-  if (workspaceList.size() > 0) {
+  if (!workspaceList.empty()) {
     Progress progress(this, 0, 1, workspaceList.size());
     for (auto it = workspaceList.begin(); it < workspaceList.end(); ++it) {
       std::size_t pos = std::distance(workspaceList.begin(), it);
diff --git a/Framework/MDAlgorithms/src/MergeMDFiles.cpp b/Framework/MDAlgorithms/src/MergeMDFiles.cpp
index 9521bba3e4d26fed868f1a34f2ef1353dadf3902..d4a8048f4147b9c4b491317cf8911ffa2ab9cac3 100644
--- a/Framework/MDAlgorithms/src/MergeMDFiles.cpp
+++ b/Framework/MDAlgorithms/src/MergeMDFiles.cpp
@@ -359,7 +359,7 @@ void MergeMDFiles::exec() {
   }
   m_Filenames =
       MultipleFileProperty::flattenFileNames(multiFileProp->operator()());
-  if (m_Filenames.size() == 0)
+  if (m_Filenames.empty())
     throw std::invalid_argument("Must specify at least one filename.");
   std::string firstFile = m_Filenames[0];
 
diff --git a/Framework/Nexus/src/NexusFileIO.cpp b/Framework/Nexus/src/NexusFileIO.cpp
index 94984b503dfdcefad66994b87fab3b002e663e25..eb27efdf8ea8a2266b6ea6b34e91ebc7166cc735 100644
--- a/Framework/Nexus/src/NexusFileIO.cpp
+++ b/Framework/Nexus/src/NexusFileIO.cpp
@@ -760,7 +760,7 @@ int NexusFileIO::writeNexusProcessedDataEventCombined(
 
   // The array of indices for each event list #
   int dims_array[1] = {static_cast<int>(indices.size())};
-  if (indices.size() > 0) {
+  if (!indices.empty()) {
     if (compress)
       NXcompmakedata(fileID, "indices", NX_INT64, 1, dims_array,
                      m_nexuscompression, dims_array);
diff --git a/Framework/RemoteAlgorithms/src/SCARFTomoReconstruction.cpp b/Framework/RemoteAlgorithms/src/SCARFTomoReconstruction.cpp
index eec7b27e714d89ca85d93b1e1ce63b769099f368..1c087ac8dc929ec964d5388b6d5ddfaa982c8419 100644
--- a/Framework/RemoteAlgorithms/src/SCARFTomoReconstruction.cpp
+++ b/Framework/RemoteAlgorithms/src/SCARFTomoReconstruction.cpp
@@ -1232,7 +1232,7 @@ void SCARFTomoReconstruction::genOutputStatusInfo(
     setProperty("RemoteJobsCommands", jobCommands);
   } else {
     // Single job query. Here the job ID is an input
-    if (0 == jobIds.size()) {
+    if (jobIds.empty()) {
       setProperty("RemoteJobName", "Unknown!");
       setProperty("RemoteJobStatus", "Unknown!");
       setProperty("RemoteJobCommand", "Unknown!");
diff --git a/Framework/RemoteJobManagers/src/LSFJobManager.cpp b/Framework/RemoteJobManagers/src/LSFJobManager.cpp
index 5a411b6d8ca9435de62f596a9613d2bc6b2c3a87..f98c974e705a6504d7cbfa698a43032ecb80d77b 100644
--- a/Framework/RemoteJobManagers/src/LSFJobManager.cpp
+++ b/Framework/RemoteJobManagers/src/LSFJobManager.cpp
@@ -1354,7 +1354,7 @@ bool LSFJobManager::findTransaction(const std::string &id) const {
 *
 */
 void LSFJobManager::addJobInTransaction(const std::string &jobID) {
-  if (g_transactions.size() <= 0)
+  if (g_transactions.empty())
     return;
   auto &jobs = g_transactions.rbegin()->second.jobIDs;
   auto it = std::find(jobs.begin(), jobs.end(), jobID);
diff --git a/Framework/RemoteJobManagers/src/MantidWebServiceAPIHelper.cpp b/Framework/RemoteJobManagers/src/MantidWebServiceAPIHelper.cpp
index 8022e369194333a233339765cee66d7bf9287ed9..a19baa058fc1d9be534a50961aca59ecba276fd7 100644
--- a/Framework/RemoteJobManagers/src/MantidWebServiceAPIHelper.cpp
+++ b/Framework/RemoteJobManagers/src/MantidWebServiceAPIHelper.cpp
@@ -63,7 +63,7 @@ std::istream &MantidWebServiceAPIHelper::httpGet(
   // session cookie.
   std::vector<Poco::Net::HTTPCookie> newCookies;
   m_response.getCookies(newCookies);
-  if (newCookies.size() > 0) {
+  if (!newCookies.empty()) {
     g_cookies = newCookies;
   }
 
@@ -152,7 +152,7 @@ std::istream &MantidWebServiceAPIHelper::httpPost(
   // session cookie.
   std::vector<Poco::Net::HTTPCookie> newCookies;
   m_response.getCookies(newCookies);
-  if (newCookies.size() > 0) {
+  if (!newCookies.empty()) {
     g_cookies = newCookies;
   }
 
diff --git a/Framework/RemoteJobManagers/src/SCARFLSFJobManager.cpp b/Framework/RemoteJobManagers/src/SCARFLSFJobManager.cpp
index 94f9e1b3c4885ae36411e9c1d1fdb785a9d12f22..35b5e2bf41e6503112c15e52f5894edfb98919c7 100644
--- a/Framework/RemoteJobManagers/src/SCARFLSFJobManager.cpp
+++ b/Framework/RemoteJobManagers/src/SCARFLSFJobManager.cpp
@@ -154,7 +154,7 @@ bool SCARFLSFJobManager::ping() {
  * logged in with authenticate().
  */
 void SCARFLSFJobManager::logout(const std::string &username) {
-  if (0 == g_tokenStash.size()) {
+  if (g_tokenStash.empty()) {
     throw std::runtime_error("Logout failed. No one is currenlty logged in.");
   }
 
diff --git a/Framework/SINQ/src/PoldiFitPeaks2D.cpp b/Framework/SINQ/src/PoldiFitPeaks2D.cpp
index bec134a194a93596e365731386f9c31be7a63a94..0d2d66898db1cc1f473c48851f18d33f583e1e6d 100644
--- a/Framework/SINQ/src/PoldiFitPeaks2D.cpp
+++ b/Framework/SINQ/src/PoldiFitPeaks2D.cpp
@@ -702,7 +702,7 @@ PoldiFitPeaks2D::getUserSpecifiedTies(const IFunction_sptr &poldiFn) {
       }
     }
 
-    if (tieComponents.size() > 0) {
+    if (!tieComponents.empty()) {
       return boost::algorithm::join(tieComponents, ",");
     }
   }
diff --git a/Framework/SINQ/src/PoldiUtilities/PoldiDeadWireDecorator.cpp b/Framework/SINQ/src/PoldiUtilities/PoldiDeadWireDecorator.cpp
index 4282351ce0911fbf04064ffcaf52a2f2859893f6..566f7e0b72aaa036bf792e2c739bc5dc8daef37a 100644
--- a/Framework/SINQ/src/PoldiUtilities/PoldiDeadWireDecorator.cpp
+++ b/Framework/SINQ/src/PoldiUtilities/PoldiDeadWireDecorator.cpp
@@ -58,7 +58,7 @@ void PoldiDeadWireDecorator::detectorSetHook() {
 
 std::vector<int>
 PoldiDeadWireDecorator::getGoodElements(std::vector<int> rawElements) {
-  if (m_deadWireSet.size() > 0) {
+  if (!m_deadWireSet.empty()) {
     if (*m_deadWireSet.rbegin() > rawElements.back()) {
       throw std::runtime_error(
           std::string("Deadwires set contains illegal index."));
diff --git a/Framework/SINQ/src/PoldiUtilities/PoldiResidualCorrelationCore.cpp b/Framework/SINQ/src/PoldiUtilities/PoldiResidualCorrelationCore.cpp
index cc7d068fa8d09991f48c65d737f0ae004fd2ee1d..09e5c2697ab01770c81c6d5a0cebe87c47502e0c 100644
--- a/Framework/SINQ/src/PoldiUtilities/PoldiResidualCorrelationCore.cpp
+++ b/Framework/SINQ/src/PoldiUtilities/PoldiResidualCorrelationCore.cpp
@@ -43,7 +43,7 @@ double PoldiResidualCorrelationCore::reduceChopperSlitList(
 /// Calculates the average of the values in a vector.
 double PoldiResidualCorrelationCore::calculateAverage(
     const std::vector<double> &values) const {
-  if (values.size() == 0) {
+  if (values.empty()) {
     throw std::runtime_error("Cannot calculate average of 0 values.");
   }
 
diff --git a/Framework/ScriptRepository/src/ScriptRepositoryImpl.cpp b/Framework/ScriptRepository/src/ScriptRepositoryImpl.cpp
index 79867493af57e6de8f550fd70cc21a8fd86243e5..5459edd363cd08d4b1103706fa3c6454cf93f0cc 100644
--- a/Framework/ScriptRepository/src/ScriptRepositoryImpl.cpp
+++ b/Framework/ScriptRepository/src/ScriptRepositoryImpl.cpp
@@ -1527,7 +1527,7 @@ void ScriptRepositoryImpl::parseDownloadedEntries(Repository &repo) {
     } // end loop FOREACH entry in local json
 
     // delete the entries to be deleted in json file
-    if (entries_to_delete.size() > 0) {
+    if (!entries_to_delete.empty()) {
 
       // clear the auto_update flag from the folders if the user deleted files
       for (const auto &folder : folders_of_deleted) {