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, 5 deletions

diff --git a/Source/cmExportCommand.cxx b/Source/cmExportCommand.cxx
index 598eafe..4046f91 100644
--- a/Source/cmExportCommand.cxx
+++ b/Source/cmExportCommand.cxx
@@ -299,8 +299,7 @@ void cmExportCommand::StorePackageRegistryWin(std::string const& package,
                                               const char* content,
                                               const char* hash)
 {
-  std::string key = "Software\\Kitware\\CMake\\Packages\\";
-  key += package;
+  std::string key = cmStrCat("Software\\Kitware\\CMake\\Packages\\", package);
   HKEY hKey;
   LONG err =
     RegCreateKeyExW(HKEY_CURRENT_USER, cmsys::Encoding::ToWide(key).c_str(), 0,
@@ -334,9 +333,7 @@ void cmExportCommand::StorePackageRegistryDir(std::string const& package,
       B_OK) {
     return;
   }
-  std::string fname = dir;
-  fname += "/cmake/packages/";
-  fname += package;
+  std::string fname = cmStrCat(dir, "/cmake/packages/", package);
 #  else
   std::string fname;
   if (!cmSystemTools::GetEnv("HOME", fname)) {