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, 2 insertions, 3 deletions

diff --git a/Source/cmSetPropertyCommand.cxx b/Source/cmSetPropertyCommand.cxx
index 72291dc919..7e3a340bab 100644
--- a/Source/cmSetPropertyCommand.cxx
+++ b/Source/cmSetPropertyCommand.cxx
@@ -242,9 +242,8 @@ bool HandleDirectoryMode(cmExecutionStatus& status,
     // respect to the current directory.
     std::string dir = *names.begin();
     if (!cmSystemTools::FileIsFullPath(dir)) {
-      dir = status.GetMakefile().GetCurrentSourceDirectory();
-      dir += "/";
-      dir += *names.begin();
+      dir = cmStrCat(status.GetMakefile().GetCurrentSourceDirectory(), '/',
+                     *names.begin());
     }
 
     // The local generators are associated with collapsed paths.