Source sweep: Use cmStrCat for string concatenation

This patch is generated by a python script that uses regular expressions to
search for string concatenation patterns of the kind

```
std::string str = <ARG0>;
str += <ARG1>;
str += <ARG2>;
...
```

and replaces them with a single `cmStrCat` call

```
std::string str = cmStrCat(<ARG0>, <ARG1>, <ARG2>, ...);
```

If any `<ARGX>` is itself a concatenated string of the kind

```
a + b + c + ...;
```

then `<ARGX>` is split into multiple arguments for the `cmStrCat` call.

If there's a sequence of literals in the `<ARGX>`, then all literals in the
sequence are concatenated and merged into a single literal argument for
the `cmStrCat` call.

Single character strings are converted to single char arguments for
the `cmStrCat` call.

`std::to_string(...)` wrappings are removed from `cmStrCat` arguments,
because it supports numeric types as well as string types.

`arg.substr(x)` arguments to `cmStrCat` are replaced with
`cm::string_view(arg).substr(x)`

20 files changed, 110 insertions, 188 deletions

diff --git a/Source/CTest/cmCTestBuildAndTestHandler.cxx b/Source/CTest/cmCTestBuildAndTestHandler.cxx
index 3aea1f4a69..e7fb4c7dcb 100644
--- a/Source/CTest/cmCTestBuildAndTestHandler.cxx
+++ b/Source/CTest/cmCTestBuildAndTestHandler.cxx
@@ -7,6 +7,7 @@
 #include "cmGlobalGenerator.h"
 #include "cmMakefile.h"
 #include "cmState.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmWorkingDirectory.h"
 #include "cmake.h"
@@ -289,9 +290,8 @@ int cmCTestBuildAndTestHandler::RunCMakeAndTest(std::string* outstring)
   std::vector<std::string> extraPaths;
   // if this->ExecutableDirectory is set try that as well
   if (!this->ExecutableDirectory.empty()) {
-    std::string tempPath = this->ExecutableDirectory;
-    tempPath += "/";
-    tempPath += this->TestCommand;
+    std::string tempPath =
+      cmStrCat(this->ExecutableDirectory, '/', this->TestCommand);
     extraPaths.push_back(tempPath);
   }
   std::vector<std::string> failed;
diff --git a/Source/CTest/cmCTestBuildCommand.cxx b/Source/CTest/cmCTestBuildCommand.cxx
index e71eafe331..6e76f08cb1 100644
--- a/Source/CTest/cmCTestBuildCommand.cxx
+++ b/Source/CTest/cmCTestBuildCommand.cxx
@@ -7,6 +7,7 @@
 #include "cmGlobalGenerator.h"
 #include "cmMakefile.h"
 #include "cmMessageType.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmake.h"
 
@@ -90,9 +91,8 @@ cmCTestGenericHandler* cmCTestBuildCommand::InitializeHandler()
           this->Makefile->GetCMakeInstance()->CreateGlobalGenerator(
             cmakeGeneratorName);
         if (!this->GlobalGenerator) {
-          std::string e = "could not create generator named \"";
-          e += cmakeGeneratorName;
-          e += "\"";
+          std::string e = cmStrCat("could not create generator named \"",
+                                   cmakeGeneratorName, '"');
           this->Makefile->IssueMessage(MessageType::FATAL_ERROR, e);
           cmSystemTools::SetFatalErrorOccured();
           return nullptr;
diff --git a/Source/CTest/cmCTestBuildHandler.cxx b/Source/CTest/cmCTestBuildHandler.cxx
index 2365a66754..8d1f76b13b 100644
--- a/Source/CTest/cmCTestBuildHandler.cxx
+++ b/Source/CTest/cmCTestBuildHandler.cxx
@@ -565,8 +565,7 @@ void cmCTestBuildHandler::GenerateXMLLogScraped(cmXMLWriter& xml)
   std::string srcdir = this->CTest->GetCTestConfiguration("SourceDirectory");
   // make sure the source dir is in the correct case on windows
   // via a call to collapse full path.
-  srcdir = cmSystemTools::CollapseFullPath(srcdir);
-  srcdir += "/";
+  srcdir = cmStrCat(cmSystemTools::CollapseFullPath(srcdir), '/');
   for (it = ew.begin();
        it != ew.end() && (numErrorsAllowed || numWarningsAllowed); it++) {
     cmCTestBuildErrorWarning* cm = &(*it);
@@ -697,10 +696,8 @@ cmCTestBuildHandler::LaunchHelper::LaunchHelper(cmCTestBuildHandler* handler)
   } else {
     // Compute a directory in which to store launcher fragments.
     std::string& launchDir = this->Handler->CTestLaunchDir;
-    launchDir = this->CTest->GetBinaryDir();
-    launchDir += "/Testing/";
-    launchDir += tag;
-    launchDir += "/Build";
+    launchDir =
+      cmStrCat(this->CTest->GetBinaryDir(), "/Testing/", tag, "/Build");
 
     // Clean out any existing launcher fragments.
     cmSystemTools::RemoveADirectory(launchDir);
@@ -709,8 +706,7 @@ cmCTestBuildHandler::LaunchHelper::LaunchHelper(cmCTestBuildHandler* handler)
       // Enable launcher fragments.
       cmSystemTools::MakeDirectory(launchDir);
       this->WriteLauncherConfig();
-      std::string launchEnv = "CTEST_LAUNCH_LOGS=";
-      launchEnv += launchDir;
+      std::string launchEnv = cmStrCat("CTEST_LAUNCH_LOGS=", launchDir);
       cmSystemTools::PutEnv(launchEnv);
     }
   }
@@ -736,8 +732,8 @@ void cmCTestBuildHandler::LaunchHelper::WriteLauncherConfig()
                             this->Handler->ReallyCustomWarningExceptions);
 
   // Give some testing configuration information to the launcher.
-  std::string fname = this->Handler->CTestLaunchDir;
-  fname += "/CTestLaunchConfig.cmake";
+  std::string fname =
+    cmStrCat(this->Handler->CTestLaunchDir, "/CTestLaunchConfig.cmake");
   cmGeneratedFileStream fout(fname);
   std::string srcdir = this->CTest->GetCTestConfiguration("SourceDirectory");
   fout << "set(CTEST_SOURCE_DIRECTORY \"" << srcdir << "\")\n";
@@ -749,10 +745,8 @@ void cmCTestBuildHandler::LaunchHelper::WriteScrapeMatchers(
   if (matchers.empty()) {
     return;
   }
-  std::string fname = this->Handler->CTestLaunchDir;
-  fname += "/Custom";
-  fname += purpose;
-  fname += ".txt";
+  std::string fname =
+    cmStrCat(this->Handler->CTestLaunchDir, "/Custom", purpose, ".txt");
   cmGeneratedFileStream fout(fname);
   for (std::string const& m : matchers) {
     fout << m << "\n";
@@ -891,9 +885,8 @@ int cmCTestBuildHandler::RunMakeCommand(const std::string& command,
         // dashboard.
         cmCTestBuildErrorWarning errorwarning;
         errorwarning.LogLine = 1;
-        errorwarning.Text =
-          "*** WARNING non-zero return value in ctest from: ";
-        errorwarning.Text += argv[0];
+        errorwarning.Text = cmStrCat(
+          "*** WARNING non-zero return value in ctest from: ", argv[0]);
         errorwarning.PreContext.clear();
         errorwarning.PostContext.clear();
         errorwarning.Error = false;
@@ -915,8 +908,8 @@ int cmCTestBuildHandler::RunMakeCommand(const std::string& command,
     // If there was an error running command, report that on the dashboard.
     cmCTestBuildErrorWarning errorwarning;
     errorwarning.LogLine = 1;
-    errorwarning.Text = "*** ERROR executing: ";
-    errorwarning.Text += cmsysProcess_GetErrorString(cp);
+    errorwarning.Text =
+      cmStrCat("*** ERROR executing: ", cmsysProcess_GetErrorString(cp));
     errorwarning.PreContext.clear();
     errorwarning.PostContext.clear();
     errorwarning.Error = true;
diff --git a/Source/CTest/cmCTestCVS.cxx b/Source/CTest/cmCTestCVS.cxx
index 9c038399e5..560c16919b 100644
--- a/Source/CTest/cmCTestCVS.cxx
+++ b/Source/CTest/cmCTestCVS.cxx
@@ -4,8 +4,10 @@
 
 #include "cmCTest.h"
 #include "cmProcessTools.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmXMLWriter.h"
+#include "cm_string_view.hxx"
 
 #include "cmsys/FStream.hxx"
 #include "cmsys/RegularExpression.hxx"
@@ -204,8 +206,7 @@ std::string cmCTestCVS::ComputeBranchFlag(std::string const& dir)
   if (tagStream && cmSystemTools::GetLineFromStream(tagStream, tagLine) &&
       tagLine.size() > 1 && tagLine[0] == 'T') {
     // Use the branch specified in the tag file.
-    std::string flag = "-r";
-    flag += tagLine.substr(1);
+    std::string flag = cmStrCat("-r", cm::string_view(tagLine).substr(1));
     return flag;
   }
   // Use the default branch.
diff --git a/Source/CTest/cmCTestConfigureCommand.cxx b/Source/CTest/cmCTestConfigureCommand.cxx
index eb7ecb583c..320c1842bf 100644
--- a/Source/CTest/cmCTestConfigureCommand.cxx
+++ b/Source/CTest/cmCTestConfigureCommand.cxx
@@ -76,9 +76,8 @@ cmCTestGenericHandler* cmCTestConfigureCommand::InitializeHandler()
         delete gg;
       }
 
-      std::string cmakeConfigureCommand = "\"";
-      cmakeConfigureCommand += cmSystemTools::GetCMakeCommand();
-      cmakeConfigureCommand += "\"";
+      std::string cmakeConfigureCommand =
+        cmStrCat('"', cmSystemTools::GetCMakeCommand(), '"');
 
       for (std::string const& option : options) {
         cmakeConfigureCommand += " \"";
diff --git a/Source/CTest/cmCTestCoverageHandler.cxx b/Source/CTest/cmCTestCoverageHandler.cxx
index 2a68544236..772fa47d26 100644
--- a/Source/CTest/cmCTestCoverageHandler.cxx
+++ b/Source/CTest/cmCTestCoverageHandler.cxx
@@ -130,10 +130,9 @@ void cmCTestCoverageHandler::Initialize()
 
 void cmCTestCoverageHandler::CleanCoverageLogFiles(std::ostream& log)
 {
-  std::string logGlob = this->CTest->GetCTestConfiguration("BuildDirectory");
-  logGlob += "/Testing/";
-  logGlob += this->CTest->GetCurrentTag();
-  logGlob += "/CoverageLog*";
+  std::string logGlob =
+    cmStrCat(this->CTest->GetCTestConfiguration("BuildDirectory"), "/Testing/",
+             this->CTest->GetCurrentTag(), "/CoverageLog*");
   cmsys::Glob gl;
   gl.FindFiles(logGlob);
   std::vector<std::string> const& files = gl.GetFiles();
@@ -1456,8 +1455,7 @@ int cmCTestCoverageHandler::HandleLCovCoverage(
       std::vector<std::string> lcovFiles;
       dir = this->CTest->GetBinaryDir();
       std::string daGlob;
-      daGlob = dir;
-      daGlob += "/*.LCOV";
+      daGlob = cmStrCat(dir, "/*.LCOV");
       cmCTestOptionalLog(
         this->CTest, HANDLER_VERBOSE_OUTPUT,
         "   looking for LCOV files in: " << daGlob << std::endl, this->Quiet);
@@ -1598,12 +1596,10 @@ void cmCTestCoverageHandler::FindGCovFiles(std::vector<std::string>& files)
     cmCTestOptionalLog(
       this->CTest, HANDLER_VERBOSE_OUTPUT,
       "   globbing for coverage in: " << lm.first << std::endl, this->Quiet);
-    std::string daGlob = lm.first;
-    daGlob += "/*.da";
+    std::string daGlob = cmStrCat(lm.first, "/*.da");
     gl.FindFiles(daGlob);
     cmAppend(files, gl.GetFiles());
-    daGlob = lm.first;
-    daGlob += "/*.gcda";
+    daGlob = cmStrCat(lm.first, "/*.gcda");
     gl.FindFiles(daGlob);
     cmAppend(files, gl.GetFiles());
   }
@@ -1632,8 +1628,7 @@ bool cmCTestCoverageHandler::FindLCovFiles(std::vector<std::string>& files)
 
   // DPI file should appear in build directory
   std::string daGlob;
-  daGlob = buildDir;
-  daGlob += "/*.dpi";
+  daGlob = cmStrCat(buildDir, "/*.dpi");
   cmCTestOptionalLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                      "   looking for dpi files in: " << daGlob << std::endl,
                      this->Quiet);
@@ -1946,10 +1941,9 @@ int cmCTestCoverageHandler::RunBullseyeCommand(
   cmCTestRunProcess runCoverageSrc;
   runCoverageSrc.SetCommand(program.c_str());
   runCoverageSrc.AddArgument(arg);
-  std::string stdoutFile = cont->BinaryDir + "/Testing/Temporary/";
-  stdoutFile += this->GetCTestInstance()->GetCurrentTag();
-  stdoutFile += "-";
-  stdoutFile += cmd;
+  std::string stdoutFile =
+    cmStrCat(cont->BinaryDir, "/Testing/Temporary/",
+             this->GetCTestInstance()->GetCurrentTag(), '-', cmd);
   std::string stderrFile = stdoutFile;
   stdoutFile += ".stdout";
   stderrFile += ".stderr";
@@ -2038,9 +2032,7 @@ int cmCTestCoverageHandler::RunBullseyeSourceSummary(
       coveredFileNames.insert(file);
       if (!cmSystemTools::FileIsFullPath(sourceFile)) {
         // file will be relative to the binary dir
-        file = cont->BinaryDir;
-        file += "/";
-        file += sourceFile;
+        file = cmStrCat(cont->BinaryDir, '/', sourceFile);
       }
       file = cmSystemTools::CollapseFullPath(file);
       bool shouldIDoCoverage =
@@ -2222,8 +2214,8 @@ int cmCTestCoverageHandler::GetLabelId(std::string const& label)
 
 void cmCTestCoverageHandler::LoadLabels()
 {
-  std::string fileList = this->CTest->GetBinaryDir();
-  fileList += "/CMakeFiles/TargetDirectories.txt";
+  std::string fileList =
+    cmStrCat(this->CTest->GetBinaryDir(), "/CMakeFiles/TargetDirectories.txt");
   cmCTestOptionalLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
                      " target directory list [" << fileList << "]\n",
                      this->Quiet);
@@ -2237,8 +2229,7 @@ void cmCTestCoverageHandler::LoadLabels()
 void cmCTestCoverageHandler::LoadLabels(const char* dir)
 {
   LabelSet& dirLabels = this->TargetDirs[dir];
-  std::string fname = dir;
-  fname += "/Labels.txt";
+  std::string fname = cmStrCat(dir, "/Labels.txt");
   cmsys::ifstream fin(fname.c_str());
   if (!fin) {
     return;
diff --git a/Source/CTest/cmCTestCurl.cxx b/Source/CTest/cmCTestCurl.cxx
index cc63e45633..40f5918c07 100644
--- a/Source/CTest/cmCTestCurl.cxx
+++ b/Source/CTest/cmCTestCurl.cxx
@@ -5,6 +5,7 @@
 #include "cmAlgorithms.h"
 #include "cmCTest.h"
 #include "cmCurl.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
 #include <ostream>
@@ -127,9 +128,7 @@ bool cmCTestCurl::UploadFile(std::string const& local_file,
     return false;
   }
   // set the url
-  std::string upload_url = url;
-  upload_url += "?";
-  upload_url += fields;
+  std::string upload_url = cmStrCat(url, '?', fields);
   ::curl_easy_setopt(this->Curl, CURLOPT_URL, upload_url.c_str());
   // now specify which file to upload
   ::curl_easy_setopt(this->Curl, CURLOPT_INFILE, ftpfile);
diff --git a/Source/CTest/cmCTestGIT.cxx b/Source/CTest/cmCTestGIT.cxx
index b832018406..c13cc80543 100644
--- a/Source/CTest/cmCTestGIT.cxx
+++ b/Source/CTest/cmCTestGIT.cxx
@@ -111,8 +111,8 @@ std::string cmCTestGIT::FindGitDir()
   else if (git_dir[0] == '/') {
     // Cygwin Git reports a full path that Cygwin understands, but we
     // are a Windows application.  Run "cygpath" to get Windows path.
-    std::string cygpath_exe = cmSystemTools::GetFilenamePath(git);
-    cygpath_exe += "/cygpath.exe";
+    std::string cygpath_exe =
+      cmStrCat(cmSystemTools::GetFilenamePath(git), "/cygpath.exe");
     if (cmSystemTools::FileExists(cygpath_exe)) {
       char const* cygpath[] = { cygpath_exe.c_str(), "-w", git_dir.c_str(),
                                 0 };
diff --git a/Source/CTest/cmCTestLaunch.cxx b/Source/CTest/cmCTestLaunch.cxx
index 4708a7112f..ac52581fe5 100644
--- a/Source/CTest/cmCTestLaunch.cxx
+++ b/Source/CTest/cmCTestLaunch.cxx
@@ -176,14 +176,8 @@ void cmCTestLaunch::ComputeFileNames()
   this->LogHash = md5.FinalizeHex();
 
   // We store stdout and stderr in temporary log files.
-  this->LogOut = this->LogDir;
-  this->LogOut += "launch-";
-  this->LogOut += this->LogHash;
-  this->LogOut += "-out.txt";
-  this->LogErr = this->LogDir;
-  this->LogErr += "launch-";
-  this->LogErr += this->LogHash;
-  this->LogErr += "-err.txt";
+  this->LogOut = cmStrCat(this->LogDir, "launch-", this->LogHash, "-out.txt");
+  this->LogErr = cmStrCat(this->LogDir, "launch-", this->LogHash, "-err.txt");
 }
 
 void cmCTestLaunch::RunChild()
@@ -282,10 +276,8 @@ void cmCTestLaunch::LoadLabels()
   }
 
   // Labels are listed in per-target files.
-  std::string fname = this->OptionBuildDir;
-  fname += "/CMakeFiles/";
-  fname += this->OptionTargetName;
-  fname += ".dir/Labels.txt";
+  std::string fname = cmStrCat(this->OptionBuildDir, "/CMakeFiles/",
+                               this->OptionTargetName, ".dir/Labels.txt");
 
   // We are interested in per-target labels for this source file.
   std::string source = this->OptionSource;
@@ -339,10 +331,9 @@ bool cmCTestLaunch::IsError() const
 void cmCTestLaunch::WriteXML()
 {
   // Name the xml file.
-  std::string logXML = this->LogDir;
-  logXML += this->IsError() ? "error-" : "warning-";
-  logXML += this->LogHash;
-  logXML += ".xml";
+  std::string logXML =
+    cmStrCat(this->LogDir, this->IsError() ? "error-" : "warning-",
+             this->LogHash, ".xml");
 
   // Use cmGeneratedFileStream to atomically create the report file.
   cmGeneratedFileStream fxml(logXML);
@@ -545,10 +536,7 @@ void cmCTestLaunch::LoadScrapeRules()
 void cmCTestLaunch::LoadScrapeRules(
   const char* purpose, std::vector<cmsys::RegularExpression>& regexps)
 {
-  std::string fname = this->LogDir;
-  fname += "Custom";
-  fname += purpose;
-  fname += ".txt";
+  std::string fname = cmStrCat(this->LogDir, "Custom", purpose, ".txt");
   cmsys::ifstream fin(fname.c_str(), std::ios::in | std::ios::binary);
   std::string line;
   cmsys::RegularExpression rex;
@@ -616,8 +604,7 @@ void cmCTestLaunch::LoadConfig()
   cm.GetCurrentSnapshot().SetDefaultDefinitions();
   cmGlobalGenerator gg(&cm);
   cmMakefile mf(&gg, cm.GetCurrentSnapshot());
-  std::string fname = this->LogDir;
-  fname += "CTestLaunchConfig.cmake";
+  std::string fname = cmStrCat(this->LogDir, "CTestLaunchConfig.cmake");
   if (cmSystemTools::FileExists(fname) && mf.ReadListFile(fname)) {
     this->SourceDir = mf.GetSafeDefinition("CTEST_SOURCE_DIRECTORY");
     cmSystemTools::ConvertToUnixSlashes(this->SourceDir);
diff --git a/Source/CTest/cmCTestRunTest.cxx b/Source/CTest/cmCTestRunTest.cxx
index fb91322081..89b585e630 100644
--- a/Source/CTest/cmCTestRunTest.cxx
+++ b/Source/CTest/cmCTestRunTest.cxx
@@ -6,6 +6,7 @@
 #include "cmCTestMemCheckHandler.h"
 #include "cmCTestMultiProcessHandler.h"
 #include "cmProcess.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmWorkingDirectory.h"
 
@@ -86,16 +87,13 @@ bool cmCTestRunTest::EndTest(size_t completed, size_t total, bool started)
     for (auto& pass : this->TestProperties->RequiredRegularExpressions) {
       if (pass.first.find(this->ProcessOutput)) {
         found = true;
-        reason = "Required regular expression found.";
-        reason += " Regex=[";
-        reason += pass.second;
-        reason += "]";
+        reason = cmStrCat("Required regular expression found. Regex=[",
+                          pass.second, ']');
         break;
       }
     }
     if (!found) {
-      reason = "Required regular expression not found.";
-      reason += " Regex=[";
+      reason = "Required regular expression not found. Regex=[";
       for (auto& pass : this->TestProperties->RequiredRegularExpressions) {
         reason += pass.second;
         reason += "\n";
@@ -108,10 +106,8 @@ bool cmCTestRunTest::EndTest(size_t completed, size_t total, bool started)
       this->FailedDependencies.empty()) {
     for (auto& fail : this->TestProperties->ErrorRegularExpressions) {
       if (fail.first.find(this->ProcessOutput)) {
-        reason = "Error regular expression found in output.";
-        reason += " Regex=[";
-        reason += fail.second;
-        reason += "]";
+        reason = cmStrCat("Error regular expression found in output. Regex=[",
+                          fail.second, ']');
         forceFail = true;
         break;
       }
@@ -121,10 +117,8 @@ bool cmCTestRunTest::EndTest(size_t completed, size_t total, bool started)
       this->FailedDependencies.empty()) {
     for (auto& skip : this->TestProperties->SkipRegularExpressions) {
       if (skip.first.find(this->ProcessOutput)) {
-        reason = "Skip regular expression found in output.";
-        reason += " Regex=[";
-        reason += skip.second;
-        reason += "]";
+        reason = cmStrCat("Skip regular expression found in output. Regex=[",
+                          skip.second, ']');
         forceSkip = true;
         break;
       }
@@ -504,12 +498,11 @@ bool cmCTestRunTest::StartTest(size_t completed, size_t total)
     this->TestProcess = cm::make_unique<cmProcess>(*this);
     std::string msg;
     if (this->CTest->GetConfigType().empty()) {
-      msg = "Test not available without configuration.";
-      msg += "  (Missing \"-C <config>\"?)";
+      msg = "Test not available without configuration.  (Missing \"-C "
+            "<config>\"?)";
     } else {
-      msg = "Test not available in configuration \"";
-      msg += this->CTest->GetConfigType();
-      msg += "\".";
+      msg = cmStrCat("Test not available in configuration \"",
+                     this->CTest->GetConfigType(), "\".");
     }
     *this->TestHandler->LogFile << msg << std::endl;
     cmCTestLog(this->CTest, ERROR_MESSAGE, msg << std::endl);
diff --git a/Source/CTest/cmCTestSVN.cxx b/Source/CTest/cmCTestSVN.cxx
index c834686d7e..dc1472b91e 100644
--- a/Source/CTest/cmCTestSVN.cxx
+++ b/Source/CTest/cmCTestSVN.cxx
@@ -6,6 +6,7 @@
 #include "cmCTest.h"
 #include "cmCTestVC.h"
 #include "cmProcessTools.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmXMLParser.h"
 #include "cmXMLWriter.h"
@@ -143,9 +144,8 @@ bool cmCTestSVN::NoteNewRevision()
     // the repository root.
     if (!svninfo.Root.empty() &&
         cmCTestSVNPathStarts(svninfo.URL, svninfo.Root)) {
-      svninfo.Base =
-        cmCTest::DecodeURL(svninfo.URL.substr(svninfo.Root.size()));
-      svninfo.Base += "/";
+      svninfo.Base = cmStrCat(
+        cmCTest::DecodeURL(svninfo.URL.substr(svninfo.Root.size())), '/');
     }
     this->Log << "Repository '" << svninfo.LocalPath
               << "' Base = " << svninfo.Base << "\n";
diff --git a/Source/CTest/cmCTestScriptHandler.cxx b/Source/CTest/cmCTestScriptHandler.cxx
index 1c40a5803b..52d4596f03 100644
--- a/Source/CTest/cmCTestScriptHandler.cxx
+++ b/Source/CTest/cmCTestScriptHandler.cxx
@@ -451,12 +451,13 @@ int cmCTestScriptHandler::ExtractVariables()
   // make sure the required info is here
   if (this->SourceDir.empty() || this->BinaryDir.empty() ||
       this->CTestCmd.empty()) {
-    std::string msg = "CTEST_SOURCE_DIRECTORY = ";
-    msg += (!this->SourceDir.empty()) ? this->SourceDir.c_str() : "(Null)";
-    msg += "\nCTEST_BINARY_DIRECTORY = ";
-    msg += (!this->BinaryDir.empty()) ? this->BinaryDir.c_str() : "(Null)";
-    msg += "\nCTEST_COMMAND = ";
-    msg += (!this->CTestCmd.empty()) ? this->CTestCmd.c_str() : "(Null)";
+    std::string msg =
+      cmStrCat("CTEST_SOURCE_DIRECTORY = ",
+               (!this->SourceDir.empty()) ? this->SourceDir.c_str() : "(Null)",
+               "\nCTEST_BINARY_DIRECTORY = ",
+               (!this->BinaryDir.empty()) ? this->BinaryDir.c_str() : "(Null)",
+               "\nCTEST_COMMAND = ",
+               (!this->CTestCmd.empty()) ? this->CTestCmd.c_str() : "(Null)");
     cmSystemTools::Error(
       "Some required settings in the configuration file were missing:\n" +
       msg);
@@ -610,10 +611,8 @@ int cmCTestScriptHandler::BackupDirectories()
   int retVal;
 
   // compute the backup names
-  this->BackupSourceDir = this->SourceDir;
-  this->BackupSourceDir += "_CMakeBackup";
-  this->BackupBinaryDir = this->BinaryDir;
-  this->BackupBinaryDir += "_CMakeBackup";
+  this->BackupSourceDir = cmStrCat(this->SourceDir, "_CMakeBackup");
+  this->BackupBinaryDir = cmStrCat(this->BinaryDir, "_CMakeBackup");
 
   // backup the binary and src directories if requested
   if (this->Backup) {
@@ -653,9 +652,7 @@ int cmCTestScriptHandler::PerformExtraUpdates()
     std::vector<std::string> cvsArgs;
     cmExpandList(eu, cvsArgs);
     if (cvsArgs.size() == 2) {
-      std::string fullCommand = command;
-      fullCommand += " update ";
-      fullCommand += cvsArgs[1];
+      std::string fullCommand = cmStrCat(command, " update ", cvsArgs[1]);
       output.clear();
       retVal = 0;
       cmCTestLog(this->CTest, HANDLER_VERBOSE_OUTPUT,
@@ -756,9 +753,7 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
   int cmakeFailed = 0;
   std::string cmakeFailedOuput;
   if (!this->CMakeCmd.empty()) {
-    command = this->CMakeCmd;
-    command += " \"";
-    command += this->SourceDir;
+    command = cmStrCat(this->CMakeCmd, " \"", this->SourceDir);
     output.clear();
     command += "\"";
     retVal = 0;
@@ -839,8 +834,7 @@ int cmCTestScriptHandler::RunConfigurationDashboard()
 bool cmCTestScriptHandler::WriteInitialCache(const char* directory,
                                              const char* text)
 {
-  std::string cacheFile = directory;
-  cacheFile += "/CMakeCache.txt";
+  std::string cacheFile = cmStrCat(directory, "/CMakeCache.txt");
   cmGeneratedFileStream fout(cacheFile);
   if (!fout) {
     return false;
@@ -905,8 +899,7 @@ bool cmCTestScriptHandler::EmptyBinaryDirectory(const char* sname)
   }
 
   // try to avoid deleting directories that we shouldn't
-  std::string check = sname;
-  check += "/CMakeCache.txt";
+  std::string check = cmStrCat(sname, "/CMakeCache.txt");
 
   if (!cmSystemTools::FileExists(check)) {
     return false;
diff --git a/Source/CTest/cmCTestTestHandler.cxx b/Source/CTest/cmCTestTestHandler.cxx
index 7ae0d2623e..4cb19f8d95 100644
--- a/Source/CTest/cmCTestTestHandler.cxx
+++ b/Source/CTest/cmCTestTestHandler.cxx
@@ -77,9 +77,7 @@ bool cmCTestSubdirCommand::InitialPass(std::vector<std::string> const& args,
     if (cmSystemTools::FileIsFullPath(arg)) {
       fname = arg;
     } else {
-      fname = cwd;
-      fname += "/";
-      fname += arg;
+      fname = cmStrCat(cwd, '/', arg);
     }
 
     if (!cmSystemTools::FileIsDirectory(fname)) {
@@ -110,8 +108,7 @@ bool cmCTestSubdirCommand::InitialPass(std::vector<std::string> const& args,
       readit = this->Makefile->ReadDependentFile(fname);
     }
     if (!readit) {
-      std::string m = "Could not find include file: ";
-      m += fname;
+      std::string m = cmStrCat("Could not find include file: ", fname);
       this->SetError(m);
       return false;
     }
@@ -150,9 +147,8 @@ bool cmCTestAddSubdirectoryCommand::InitialPass(
     return false;
   }
 
-  std::string fname = cmSystemTools::GetCurrentWorkingDirectory();
-  fname += "/";
-  fname += args[0];
+  std::string fname =
+    cmStrCat(cmSystemTools::GetCurrentWorkingDirectory(), '/', args[0]);
 
   if (!cmSystemTools::FileExists(fname)) {
     // No subdirectory? So what...
@@ -176,8 +172,7 @@ bool cmCTestAddSubdirectoryCommand::InitialPass(
     readit = this->Makefile->ReadDependentFile(fname);
   }
   if (!readit) {
-    std::string m = "Could not find include file: ";
-    m += fname;
+    std::string m = cmStrCat("Could not find include file: ", fname);
     this->SetError(m);
     return false;
   }
@@ -1552,50 +1547,32 @@ void cmCTestTestHandler::AddConfigurations(
   attemptedConfigs.emplace_back();
 
   if (!ctest->GetConfigType().empty()) {
-    tempPath = filepath;
-    tempPath += ctest->GetConfigType();
-    tempPath += "/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, ctest->GetConfigType(), '/', filename);
     attempted.push_back(tempPath);
     attemptedConfigs.push_back(ctest->GetConfigType());
     // If the file is an OSX bundle then the configtype
     // will be at the start of the path
-    tempPath = ctest->GetConfigType();
-    tempPath += "/";
-    tempPath += filepath;
-    tempPath += filename;
+    tempPath = cmStrCat(ctest->GetConfigType(), '/', filepath, filename);
     attempted.push_back(tempPath);
     attemptedConfigs.push_back(ctest->GetConfigType());
   } else {
     // no config specified - try some options...
-    tempPath = filepath;
-    tempPath += "Release/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "Release/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("Release");
-    tempPath = filepath;
-    tempPath += "Debug/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "Debug/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("Debug");
-    tempPath = filepath;
-    tempPath += "MinSizeRel/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "MinSizeRel/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("MinSizeRel");
-    tempPath = filepath;
-    tempPath += "RelWithDebInfo/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "RelWithDebInfo/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("RelWithDebInfo");
-    tempPath = filepath;
-    tempPath += "Deployment/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "Deployment/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("Deployment");
-    tempPath = filepath;
-    tempPath += "Development/";
-    tempPath += filename;
+    tempPath = cmStrCat(filepath, "Development/", filename);
     attempted.push_back(tempPath);
     attemptedConfigs.emplace_back("Deployment");
   }
@@ -1649,8 +1626,8 @@ std::string cmCTestTestHandler::FindExecutable(
     // then try with the exe extension
     else {
       failed.push_back(attempted[ai]);
-      tempPath = attempted[ai];
-      tempPath += cmSystemTools::GetExecutableExtension();
+      tempPath =
+        cmStrCat(attempted[ai], cmSystemTools::GetExecutableExtension());
       if (cmSystemTools::FileExists(tempPath) &&
           !cmSystemTools::FileIsDirectory(tempPath)) {
         fullPath = cmSystemTools::CollapseFullPath(tempPath);
diff --git a/Source/CTest/cmCTestUpdateHandler.cxx b/Source/CTest/cmCTestUpdateHandler.cxx
index d80b5a5a06..a6a354259e 100644
--- a/Source/CTest/cmCTestUpdateHandler.cxx
+++ b/Source/CTest/cmCTestUpdateHandler.cxx
@@ -12,6 +12,7 @@
 #include "cmCTestSVN.h"
 #include "cmCTestVC.h"
 #include "cmGeneratedFileStream.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmVersion.h"
 #include "cmXMLWriter.h"
@@ -266,33 +267,27 @@ int cmCTestUpdateHandler::DetectVCS(const char* dir)
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_SVN;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/CVS";
+  sourceDirectory = cmStrCat(dir, "/CVS");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_CVS;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/.bzr";
+  sourceDirectory = cmStrCat(dir, "/.bzr");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_BZR;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/.git";
+  sourceDirectory = cmStrCat(dir, "/.git");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_GIT;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/.hg";
+  sourceDirectory = cmStrCat(dir, "/.hg");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_HG;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/.p4";
+  sourceDirectory = cmStrCat(dir, "/.p4");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_P4;
   }
-  sourceDirectory = dir;
-  sourceDirectory += "/.p4config";
+  sourceDirectory = cmStrCat(dir, "/.p4config");
   if (cmSystemTools::FileExists(sourceDirectory)) {
     return cmCTestUpdateHandler::e_P4;
   }
diff --git a/Source/CTest/cmParseCacheCoverage.cxx b/Source/CTest/cmParseCacheCoverage.cxx
index ca1fe70e45..cd2bb1a76c 100644
--- a/Source/CTest/cmParseCacheCoverage.cxx
+++ b/Source/CTest/cmParseCacheCoverage.cxx
@@ -2,6 +2,7 @@
 
 #include "cmCTest.h"
 #include "cmCTestCoverageHandler.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
 #include "cmsys/Directory.hxx"
@@ -30,9 +31,7 @@ bool cmParseCacheCoverage::LoadCoverageData(const char* d)
   for (i = 0; i < numf; i++) {
     std::string file = dir.GetFile(i);
     if (file != "." && file != ".." && !cmSystemTools::FileIsDirectory(file)) {
-      std::string path = d;
-      path += "/";
-      path += file;
+      std::string path = cmStrCat(d, '/', file);
       if (cmSystemTools::GetFilenameLastExtension(path) == ".cmcov") {
         if (!this->ReadCMCovFile(path.c_str())) {
           return false;
diff --git a/Source/CTest/cmParseGTMCoverage.cxx b/Source/CTest/cmParseGTMCoverage.cxx
index 881bf2d3b8..621ca791a7 100644
--- a/Source/CTest/cmParseGTMCoverage.cxx
+++ b/Source/CTest/cmParseGTMCoverage.cxx
@@ -31,9 +31,7 @@ bool cmParseGTMCoverage::LoadCoverageData(const char* d)
   for (i = 0; i < numf; i++) {
     std::string file = dir.GetFile(i);
     if (file != "." && file != ".." && !cmSystemTools::FileIsDirectory(file)) {
-      std::string path = d;
-      path += "/";
-      path += file;
+      std::string path = cmStrCat(d, '/', file);
       if (cmSystemTools::GetFilenameLastExtension(path) == ".mcov") {
         if (!this->ReadMCovFile(path.c_str())) {
           return false;
diff --git a/Source/CTest/cmParseJacocoCoverage.cxx b/Source/CTest/cmParseJacocoCoverage.cxx
index 5f1e712cd3..374acade01 100644
--- a/Source/CTest/cmParseJacocoCoverage.cxx
+++ b/Source/CTest/cmParseJacocoCoverage.cxx
@@ -104,9 +104,7 @@ protected:
                                 std::string const& baseDir)
   {
     // Search for the file in the baseDir and its subdirectories.
-    std::string packageGlob = baseDir;
-    packageGlob += "/";
-    packageGlob += fileName;
+    std::string packageGlob = cmStrCat(baseDir, '/', fileName);
     cmsys::Glob gl;
     gl.RecurseOn();
     gl.RecurseThroughSymlinksOn();
diff --git a/Source/CTest/cmParseMumpsCoverage.cxx b/Source/CTest/cmParseMumpsCoverage.cxx
index 4a81ee4f70..afd7dc368a 100644
--- a/Source/CTest/cmParseMumpsCoverage.cxx
+++ b/Source/CTest/cmParseMumpsCoverage.cxx
@@ -2,6 +2,7 @@
 
 #include "cmCTest.h"
 #include "cmCTestCoverageHandler.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
 #include "cmsys/FStream.hxx"
@@ -107,8 +108,7 @@ bool cmParseMumpsCoverage::LoadPackages(const char* d)
 {
   cmsys::Glob glob;
   glob.RecurseOn();
-  std::string pat = d;
-  pat += "/*.m";
+  std::string pat = cmStrCat(d, "/*.m");
   glob.FindFiles(pat);
   for (std::string& file : glob.GetFiles()) {
     std::string name = cmSystemTools::GetFilenameName(file);
diff --git a/Source/CTest/cmParsePHPCoverage.cxx b/Source/CTest/cmParsePHPCoverage.cxx
index a6e65c9df6..870e2229ef 100644
--- a/Source/CTest/cmParsePHPCoverage.cxx
+++ b/Source/CTest/cmParsePHPCoverage.cxx
@@ -2,6 +2,7 @@
 
 #include "cmCTest.h"
 #include "cmCTestCoverageHandler.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
 #include "cmsys/Directory.hxx"
@@ -210,9 +211,7 @@ bool cmParsePHPCoverage::ReadPHPCoverageDirectory(const char* d)
   for (i = 0; i < numf; i++) {
     std::string file = dir.GetFile(i);
     if (file != "." && file != ".." && !cmSystemTools::FileIsDirectory(file)) {
-      std::string path = d;
-      path += "/";
-      path += file;
+      std::string path = cmStrCat(d, '/', file);
       if (!this->ReadPHPData(path.c_str())) {
         return false;
       }
diff --git a/Source/CTest/cmProcess.cxx b/Source/CTest/cmProcess.cxx
index 7a3b82e612..61d2ed348f 100644
--- a/Source/CTest/cmProcess.cxx
+++ b/Source/CTest/cmProcess.cxx
@@ -7,6 +7,7 @@
 #include "cmCTestRunTest.h"
 #include "cmCTestTestHandler.h"
 #include "cmGetPipes.h"
+#include "cmStringAlgorithms.h"
 #include "cmsys/Process.h"
 
 #include <iostream>
@@ -694,8 +695,7 @@ std::string cmProcess::GetExitExceptionString()
 #    endif
 #  endif
     default:
-      exception_str = "Signal ";
-      exception_str += std::to_string(this->Signal);
+      exception_str = cmStrCat("Signal ", this->Signal);
   }
 #endif
   return exception_str;