Reduce raw string pointers usage.

* Change some functions to take `std::string` instead of
  `const char*` in the following classes: `cmMakeFile`, `cmake`,
  `cmCoreTryCompile`, `cmSystemTools`,  `cmState`, `cmLocalGenerator`
  and a few others.
* Greatly reduce using of `const char*` overloads for
  `cmSystemTools::MakeDirectory` and `cmSystemTools::RelativePath`.
* Remove many redundant `c_str()` conversions throughout the code.

1 files changed, 2 insertions, 2 deletions

diff --git a/Source/cmInstallProgramsCommand.cxx b/Source/cmInstallProgramsCommand.cxx
index 5ee81fb..f01a4c1 100644
--- a/Source/cmInstallProgramsCommand.cxx
+++ b/Source/cmInstallProgramsCommand.cxx
@@ -109,11 +109,11 @@ std::string cmInstallProgramsCommand::FindInstallSource(const char* name) const
   ts += "/";
   ts += name;
 
-  if (cmSystemTools::FileExists(tb.c_str())) {
+  if (cmSystemTools::FileExists(tb)) {
     // The file exists in the binary tree.  Use it.
     return tb;
   }
-  if (cmSystemTools::FileExists(ts.c_str())) {
+  if (cmSystemTools::FileExists(ts)) {
     // The file exists in the source tree.  Use it.
     return ts;
   }