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)`

1 files changed, 3 insertions, 2 deletions

diff --git a/Source/CTest/cmCTestCVS.cxx b/Source/CTest/cmCTestCVS.cxx
index 9c03839..560c169 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.