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, 8 insertions, 12 deletions

diff --git a/Source/cmQtAutoGen.cxx b/Source/cmQtAutoGen.cxx
index fe04fba..9d29e5c 100644
--- a/Source/cmQtAutoGen.cxx
+++ b/Source/cmQtAutoGen.cxx
@@ -292,9 +292,8 @@ static bool RccListParseOutput(std::string const& rccStdOut,
 
         std::string::size_type pos = eline.find(searchString);
         if (pos == std::string::npos) {
-          error = "rcc lists unparsable output:\n";
-          error += cmQtAutoGen::Quoted(eline);
-          error += "\n";
+          error = cmStrCat("rcc lists unparsable output:\n",
+                           cmQtAutoGen::Quoted(eline), '\n');
           return false;
         }
         pos += searchString.length();
@@ -323,9 +322,8 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
   error.clear();
 
   if (!cmSystemTools::FileExists(qrcFile, true)) {
-    error = "The resource file ";
-    error += Quoted(qrcFile);
-    error += " does not exist.";
+    error =
+      cmStrCat("The resource file ", Quoted(qrcFile), " does not exist.");
     return false;
   }
 
@@ -361,9 +359,8 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
         cmSystemTools::OUTPUT_NONE, cmDuration::zero(), cmProcessOutput::Auto);
     }
     if (!result || retVal) {
-      error = "The rcc list process failed for ";
-      error += Quoted(qrcFile);
-      error += "\n";
+      error =
+        cmStrCat("The rcc list process failed for ", Quoted(qrcFile), '\n');
       if (!rccStdOut.empty()) {
         error += rccStdOut;
         error += "\n";
@@ -389,9 +386,8 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
           osst << ifs.rdbuf();
           qrcContents = osst.str();
         } else {
-          error = "The resource file ";
-          error += Quoted(qrcFile);
-          error += " is not readable\n";
+          error = cmStrCat("The resource file ", Quoted(qrcFile),
+                           " is not readable\n");
           return false;
         }
       }