diff --git a/Source/cmAddCompileOptionsCommand.cxx b/Source/cmAddCompileOptionsCommand.cxx
index 2223cf47b..cbba831fe 100644
--- a/Source/cmAddCompileOptionsCommand.cxx
+++ b/Source/cmAddCompileOptionsCommand.cxx
@@ -14,7 +14,7 @@
 bool cmAddCompileOptionsCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmAddCustomTargetCommand.cxx b/Source/cmAddCustomTargetCommand.cxx
index 9dc7c590f..8e149669b 100644
--- a/Source/cmAddCustomTargetCommand.cxx
+++ b/Source/cmAddCustomTargetCommand.cxx
@@ -18,7 +18,7 @@
 bool cmAddCustomTargetCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmAddDefinitionsCommand.cxx b/Source/cmAddDefinitionsCommand.cxx
index 2d0d02617..5f2b32f82 100644
--- a/Source/cmAddDefinitionsCommand.cxx
+++ b/Source/cmAddDefinitionsCommand.cxx
@@ -16,7 +16,7 @@ bool cmAddDefinitionsCommand::InitialPass(std::vector<std::string> const& args,
                                           cmExecutionStatus&)
 {
   // it is OK to have no arguments
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmAddLibraryCommand.cxx b/Source/cmAddLibraryCommand.cxx
index 4516ed24a..5a4005094 100644
--- a/Source/cmAddLibraryCommand.cxx
+++ b/Source/cmAddLibraryCommand.cxx
@@ -18,7 +18,7 @@
 bool cmAddLibraryCommand::InitialPass(std::vector<std::string> const& args,
                                       cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmAddSubDirectoryCommand.cxx b/Source/cmAddSubDirectoryCommand.cxx
index 63a905189..1a781ccdb 100644
--- a/Source/cmAddSubDirectoryCommand.cxx
+++ b/Source/cmAddSubDirectoryCommand.cxx
@@ -15,7 +15,7 @@
 bool cmAddSubDirectoryCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmBuildCommand.cxx b/Source/cmBuildCommand.cxx
index 98308670f..6146053dc 100644
--- a/Source/cmBuildCommand.cxx
+++ b/Source/cmBuildCommand.cxx
@@ -27,7 +27,7 @@ bool cmBuildCommand::InitialPass(std::vector<std::string> const& args,
 
 bool cmBuildCommand::MainSignature(std::vector<std::string> const& args)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("requires at least one argument naming a CMake variable");
     return false;
   }
diff --git a/Source/cmBuildNameCommand.cxx b/Source/cmBuildNameCommand.cxx
index 27234d73c..3d0203439 100644
--- a/Source/cmBuildNameCommand.cxx
+++ b/Source/cmBuildNameCommand.cxx
@@ -22,7 +22,7 @@ bool cmBuildNameCommand::InitialPass(std::vector<std::string> const& args,
         "The build_name command should not be called; see CMP0036.")) {
     return true;
   }
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmCMakePolicyCommand.cxx b/Source/cmCMakePolicyCommand.cxx
index 07e0885ab..03c4a3710 100644
--- a/Source/cmCMakePolicyCommand.cxx
+++ b/Source/cmCMakePolicyCommand.cxx
@@ -17,7 +17,7 @@
 bool cmCMakePolicyCommand::InitialPass(std::vector<std::string> const& args,
                                        cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("requires at least one argument.");
     return false;
   }
diff --git a/Source/cmConditionEvaluator.cxx b/Source/cmConditionEvaluator.cxx
index 94f03e851..e670dc6fd 100644
--- a/Source/cmConditionEvaluator.cxx
+++ b/Source/cmConditionEvaluator.cxx
@@ -85,7 +85,7 @@ bool cmConditionEvaluator::IsTrue(
   errorString = "";
 
   // handle empty invocation
-  if (args.size() < 1) {
+  if (args.empty()) {
     return false;
   }
 
diff --git a/Source/cmDefinePropertyCommand.cxx b/Source/cmDefinePropertyCommand.cxx
index 484a97017..358952907 100644
--- a/Source/cmDefinePropertyCommand.cxx
+++ b/Source/cmDefinePropertyCommand.cxx
@@ -17,7 +17,7 @@
 bool cmDefinePropertyCommand::InitialPass(std::vector<std::string> const& args,
                                           cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmEnableLanguageCommand.cxx b/Source/cmEnableLanguageCommand.cxx
index 0ebe77846..9b7dd0394 100644
--- a/Source/cmEnableLanguageCommand.cxx
+++ b/Source/cmEnableLanguageCommand.cxx
@@ -17,7 +17,7 @@ bool cmEnableLanguageCommand::InitialPass(std::vector<std::string> const& args,
 {
   bool optional = false;
   std::vector<std::string> languages;
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmExecProgramCommand.cxx b/Source/cmExecProgramCommand.cxx
index 58bbc3156..284f48621 100644
--- a/Source/cmExecProgramCommand.cxx
+++ b/Source/cmExecProgramCommand.cxx
@@ -19,7 +19,7 @@
 bool cmExecProgramCommand::InitialPass(std::vector<std::string> const& args,
                                        cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmExecuteProcessCommand.cxx b/Source/cmExecuteProcessCommand.cxx
index d97b25f8e..81d8a1fa9 100644
--- a/Source/cmExecuteProcessCommand.cxx
+++ b/Source/cmExecuteProcessCommand.cxx
@@ -31,7 +31,7 @@ void cmExecuteProcessCommandAppend(std::vector<char>& output, const char* data,
 bool cmExecuteProcessCommand::InitialPass(std::vector<std::string> const& args,
                                           cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmExportBuildAndroidMKGenerator.cxx b/Source/cmExportBuildAndroidMKGenerator.cxx
index 3247cc853..96080a9a7 100644
--- a/Source/cmExportBuildAndroidMKGenerator.cxx
+++ b/Source/cmExportBuildAndroidMKGenerator.cxx
@@ -69,7 +69,7 @@ void cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
   const ImportPropertyMap& properties)
 {
   std::string config = "";
-  if (this->Configurations.size()) {
+  if (!this->Configurations.empty()) {
     config = this->Configurations[0];
   }
   cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
diff --git a/Source/cmExportInstallAndroidMKGenerator.cxx b/Source/cmExportInstallAndroidMKGenerator.cxx
index 8f815b708..10ba6eeb4 100644
--- a/Source/cmExportInstallAndroidMKGenerator.cxx
+++ b/Source/cmExportInstallAndroidMKGenerator.cxx
@@ -76,7 +76,7 @@ void cmExportInstallAndroidMKGenerator::GenerateImportTargetCode(
   os << "LOCAL_SRC_FILES := $(_IMPORT_PREFIX)/";
   os << target->Target->GetProperty("__dest") << "/";
   std::string config = "";
-  if (this->Configurations.size()) {
+  if (!this->Configurations.empty()) {
     config = this->Configurations[0];
   }
   os << target->GetFullName(config) << "\n";
@@ -103,7 +103,7 @@ void cmExportInstallAndroidMKGenerator::GenerateInterfaceProperties(
   const ImportPropertyMap& properties)
 {
   std::string config = "";
-  if (this->Configurations.size()) {
+  if (!this->Configurations.empty()) {
     config = this->Configurations[0];
   }
   cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
diff --git a/Source/cmExportLibraryDependenciesCommand.cxx b/Source/cmExportLibraryDependenciesCommand.cxx
index b422a2c85..d9c30e77a 100644
--- a/Source/cmExportLibraryDependenciesCommand.cxx
+++ b/Source/cmExportLibraryDependenciesCommand.cxx
@@ -27,7 +27,7 @@ bool cmExportLibraryDependenciesCommand::InitialPass(
         "see CMP0033.")) {
     return true;
   }
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmFindPackageCommand.cxx b/Source/cmFindPackageCommand.cxx
index 72b53200c..405dce313 100644
--- a/Source/cmFindPackageCommand.cxx
+++ b/Source/cmFindPackageCommand.cxx
@@ -130,7 +130,7 @@ void cmFindPackageCommand::AppendSearchPathGroups()
 bool cmFindPackageCommand::InitialPass(std::vector<std::string> const& args,
                                        cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmForEachCommand.cxx b/Source/cmForEachCommand.cxx
index c6e5f0665..dadd08034 100644
--- a/Source/cmForEachCommand.cxx
+++ b/Source/cmForEachCommand.cxx
@@ -113,7 +113,7 @@ bool cmForEachFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
 bool cmForEachCommand::InitialPass(std::vector<std::string> const& args,
                                    cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmFunctionCommand.cxx b/Source/cmFunctionCommand.cxx
index 40c54dbdc..bda96aa21 100644
--- a/Source/cmFunctionCommand.cxx
+++ b/Source/cmFunctionCommand.cxx
@@ -202,7 +202,7 @@ bool cmFunctionFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
 bool cmFunctionCommand::InitialPass(std::vector<std::string> const& args,
                                     cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmIncludeCommand.cxx b/Source/cmIncludeCommand.cxx
index 360ebeb4b..c90314e1e 100644
--- a/Source/cmIncludeCommand.cxx
+++ b/Source/cmIncludeCommand.cxx
@@ -15,7 +15,7 @@
 bool cmIncludeCommand::InitialPass(std::vector<std::string> const& args,
                                    cmExecutionStatus&)
 {
-  if (args.size() < 1 || args.size() > 4) {
+  if (args.empty() || args.size() > 4) {
     this->SetError("called with wrong number of arguments.  "
                    "include() only takes one file.");
     return false;
diff --git a/Source/cmIncludeDirectoryCommand.cxx b/Source/cmIncludeDirectoryCommand.cxx
index cafdba788..904fcca21 100644
--- a/Source/cmIncludeDirectoryCommand.cxx
+++ b/Source/cmIncludeDirectoryCommand.cxx
@@ -15,7 +15,7 @@
 bool cmIncludeDirectoryCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmIncludeRegularExpressionCommand.cxx b/Source/cmIncludeRegularExpressionCommand.cxx
index 2473dff56..bd26d93f0 100644
--- a/Source/cmIncludeRegularExpressionCommand.cxx
+++ b/Source/cmIncludeRegularExpressionCommand.cxx
@@ -15,7 +15,7 @@
 bool cmIncludeRegularExpressionCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if ((args.size() < 1) || (args.size() > 2)) {
+  if ((args.empty()) || (args.size() > 2)) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmLinkDirectoriesCommand.cxx b/Source/cmLinkDirectoriesCommand.cxx
index a33b429d7..9b5d54a85 100644
--- a/Source/cmLinkDirectoriesCommand.cxx
+++ b/Source/cmLinkDirectoriesCommand.cxx
@@ -15,7 +15,7 @@
 bool cmLinkDirectoriesCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmLinkLibrariesCommand.cxx b/Source/cmLinkLibrariesCommand.cxx
index 5d23d6a59..bef234e9e 100644
--- a/Source/cmLinkLibrariesCommand.cxx
+++ b/Source/cmLinkLibrariesCommand.cxx
@@ -15,7 +15,7 @@
 bool cmLinkLibrariesCommand::InitialPass(std::vector<std::string> const& args,
                                          cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
   // add libraries, nothe that there is an optional prefix
diff --git a/Source/cmLinkedTree.h b/Source/cmLinkedTree.h
index 466aaa7d7..025c0a34d 100644
--- a/Source/cmLinkedTree.h
+++ b/Source/cmLinkedTree.h
@@ -167,10 +167,10 @@ public:
 
   iterator Truncate()
   {
-    assert(this->UpPositions.size() > 0);
+    assert(!this->UpPositions.empty());
     this->UpPositions.erase(this->UpPositions.begin() + 1,
                             this->UpPositions.end());
-    assert(this->Data.size() > 0);
+    assert(!this->Data.empty());
     this->Data.erase(this->Data.begin() + 1, this->Data.end());
     return iterator(this, 1);
   }
diff --git a/Source/cmLoadCacheCommand.cxx b/Source/cmLoadCacheCommand.cxx
index 85188d19d..6d9cf8ee0 100644
--- a/Source/cmLoadCacheCommand.cxx
+++ b/Source/cmLoadCacheCommand.cxx
@@ -18,7 +18,7 @@
 bool cmLoadCacheCommand::InitialPass(std::vector<std::string> const& args,
                                      cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with wrong number of arguments.");
   }
 
diff --git a/Source/cmLoadCommandCommand.cxx b/Source/cmLoadCommandCommand.cxx
index ddf6ce6c9..4d8a4e3f4 100644
--- a/Source/cmLoadCommandCommand.cxx
+++ b/Source/cmLoadCommandCommand.cxx
@@ -183,7 +183,7 @@ bool cmLoadCommandCommand::InitialPass(std::vector<std::string> const& args,
         "The load_command command should not be called; see CMP0031.")) {
     return true;
   }
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmMacroCommand.cxx b/Source/cmMacroCommand.cxx
index ee9dc8af7..523106275 100644
--- a/Source/cmMacroCommand.cxx
+++ b/Source/cmMacroCommand.cxx
@@ -236,7 +236,7 @@ bool cmMacroFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
 bool cmMacroCommand::InitialPass(std::vector<std::string> const& args,
                                  cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmMarkAsAdvancedCommand.cxx b/Source/cmMarkAsAdvancedCommand.cxx
index 2fb6a75d8..6c979f607 100644
--- a/Source/cmMarkAsAdvancedCommand.cxx
+++ b/Source/cmMarkAsAdvancedCommand.cxx
@@ -15,7 +15,7 @@
 bool cmMarkAsAdvancedCommand::InitialPass(std::vector<std::string> const& args,
                                           cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmMathCommand.cxx b/Source/cmMathCommand.cxx
index ca8b926f9..b812349bf 100644
--- a/Source/cmMathCommand.cxx
+++ b/Source/cmMathCommand.cxx
@@ -16,7 +16,7 @@
 bool cmMathCommand::InitialPass(std::vector<std::string> const& args,
                                 cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("must be called with at least one argument.");
     return false;
   }
diff --git a/Source/cmMessageCommand.cxx b/Source/cmMessageCommand.cxx
index c48910e03..e88453166 100644
--- a/Source/cmMessageCommand.cxx
+++ b/Source/cmMessageCommand.cxx
@@ -17,7 +17,7 @@
 bool cmMessageCommand::InitialPass(std::vector<std::string> const& args,
                                    cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmProjectCommand.cxx b/Source/cmProjectCommand.cxx
index 139303b02..6f98d9473 100644
--- a/Source/cmProjectCommand.cxx
+++ b/Source/cmProjectCommand.cxx
@@ -15,7 +15,7 @@
 bool cmProjectCommand::InitialPass(std::vector<std::string> const& args,
                                    cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("PROJECT called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmRemoveCommand.cxx b/Source/cmRemoveCommand.cxx
index 955f71280..c695374c6 100644
--- a/Source/cmRemoveCommand.cxx
+++ b/Source/cmRemoveCommand.cxx
@@ -15,7 +15,7 @@
 bool cmRemoveCommand::InitialPass(std::vector<std::string> const& args,
                                   cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmRemoveDefinitionsCommand.cxx b/Source/cmRemoveDefinitionsCommand.cxx
index 638eda620..77de846cd 100644
--- a/Source/cmRemoveDefinitionsCommand.cxx
+++ b/Source/cmRemoveDefinitionsCommand.cxx
@@ -16,7 +16,7 @@ bool cmRemoveDefinitionsCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
   // it is OK to have no arguments
-  if (args.size() < 1) {
+  if (args.empty()) {
     return true;
   }
 
diff --git a/Source/cmSetCommand.cxx b/Source/cmSetCommand.cxx
index 8fb6aa057..6bdb28b23 100644
--- a/Source/cmSetCommand.cxx
+++ b/Source/cmSetCommand.cxx
@@ -15,7 +15,7 @@
 bool cmSetCommand::InitialPass(std::vector<std::string> const& args,
                                cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmSetDirectoryPropertiesCommand.cxx b/Source/cmSetDirectoryPropertiesCommand.cxx
index ca758dabc..858411867 100644
--- a/Source/cmSetDirectoryPropertiesCommand.cxx
+++ b/Source/cmSetDirectoryPropertiesCommand.cxx
@@ -17,7 +17,7 @@
 bool cmSetDirectoryPropertiesCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmSetTestsPropertiesCommand.cxx b/Source/cmSetTestsPropertiesCommand.cxx
index 2fb137f26..59d569d78 100644
--- a/Source/cmSetTestsPropertiesCommand.cxx
+++ b/Source/cmSetTestsPropertiesCommand.cxx
@@ -18,7 +18,7 @@
 bool cmSetTestsPropertiesCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmSourceGroupCommand.cxx b/Source/cmSourceGroupCommand.cxx
index 6db14c0a4..6f7ef6c1b 100644
--- a/Source/cmSourceGroupCommand.cxx
+++ b/Source/cmSourceGroupCommand.cxx
@@ -15,7 +15,7 @@
 bool cmSourceGroupCommand::InitialPass(std::vector<std::string> const& args,
                                        cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmStringCommand.cxx b/Source/cmStringCommand.cxx
index 3c913eec6..addfed435 100644
--- a/Source/cmStringCommand.cxx
+++ b/Source/cmStringCommand.cxx
@@ -26,7 +26,7 @@
 bool cmStringCommand::InitialPass(std::vector<std::string> const& args,
                                   cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("must be called with at least one argument.");
     return false;
   }
diff --git a/Source/cmSubdirCommand.cxx b/Source/cmSubdirCommand.cxx
index 401f588c4..48939784b 100644
--- a/Source/cmSubdirCommand.cxx
+++ b/Source/cmSubdirCommand.cxx
@@ -15,7 +15,7 @@
 bool cmSubdirCommand::InitialPass(std::vector<std::string> const& args,
                                   cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmTargetLinkLibrariesCommand.cxx b/Source/cmTargetLinkLibrariesCommand.cxx
index 1c4a9ceca..b62e225d7 100644
--- a/Source/cmTargetLinkLibrariesCommand.cxx
+++ b/Source/cmTargetLinkLibrariesCommand.cxx
@@ -22,7 +22,7 @@ bool cmTargetLinkLibrariesCommand::InitialPass(
   std::vector<std::string> const& args, cmExecutionStatus&)
 {
   // must have one argument
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmUnsetCommand.cxx b/Source/cmUnsetCommand.cxx
index 05ba65a16..5bf137c58 100644
--- a/Source/cmUnsetCommand.cxx
+++ b/Source/cmUnsetCommand.cxx
@@ -15,7 +15,7 @@
 bool cmUnsetCommand::InitialPass(std::vector<std::string> const& args,
                                  cmExecutionStatus&)
 {
-  if (args.size() < 1 || args.size() > 2) {
+  if (args.empty() || args.size() > 2) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }
diff --git a/Source/cmVariableWatchCommand.cxx b/Source/cmVariableWatchCommand.cxx
index f30ffe8f4..cf740db3a 100644
--- a/Source/cmVariableWatchCommand.cxx
+++ b/Source/cmVariableWatchCommand.cxx
@@ -104,7 +104,7 @@ cmVariableWatchCommand::~cmVariableWatchCommand()
 bool cmVariableWatchCommand::InitialPass(std::vector<std::string> const& args,
                                          cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("must be called with at least one argument.");
     return false;
   }
diff --git a/Source/cmWhileCommand.cxx b/Source/cmWhileCommand.cxx
index 93a62717e..ad558fea0 100644
--- a/Source/cmWhileCommand.cxx
+++ b/Source/cmWhileCommand.cxx
@@ -133,7 +133,7 @@ bool cmWhileFunctionBlocker::ShouldRemove(const cmListFileFunction& lff,
 bool cmWhileCommand::InvokeInitialPass(
   const std::vector<cmListFileArgument>& args, cmExecutionStatus&)
 {
-  if (args.size() < 1) {
+  if (args.empty()) {
     this->SetError("called with incorrect number of arguments");
     return false;
   }