Source sweep: Replace std::ostringstream when used with a single append

This replaces `std::ostringstream`, when it is written to only once.
If the single written argument was numeric, `std::to_string` is used instead.
Otherwise, the single written argument is used directly instead of the
`std::ostringstream::str()` invocation.

Source/CTest/cmCTestRunScriptCommand.cxx

@@ -5,8 +5,6 @@
 #include "cmCTestScriptHandler.h"
 #include "cmMakefile.h"
 
-#include <sstream>
-
 class cmExecutionStatus;
 
 bool cmCTestRunScriptCommand::InitialPass(std::vector<std::string> const& args,
@@ -41,9 +39,7 @@ bool cmCTestRunScriptCommand::InitialPass(std::vector<std::string> const& args,
       int ret;
       cmCTestScriptHandler::RunScript(this->CTest, this->Makefile,
                                       args[i].c_str(), !np, &ret);
-      std::ostringstream str;
-      str << ret;
-      this->Makefile->AddDefinition(returnVariable, str.str());
+      this->Makefile->AddDefinition(returnVariable, std::to_string(ret));
     }
   }
   return true;