cmstd: Modernize CMake system headers

Provide a standardized way to handle the C++ "standard" headers
customized to be used with current CMake C++ standard constraints.
Offer under directory `cm` headers which can be used as direct
replacements of the standard ones.  For example:

    #include <cm/string_view>

can be used safely for CMake development in place of the `<string_view>`
standard header.

Fixes: #19491

1 files changed, 6 insertions, 5 deletions

diff --git a/Source/cmStateDirectory.cxx b/Source/cmStateDirectory.cxx
index ede00a0..1262f53 100644
--- a/Source/cmStateDirectory.cxx
+++ b/Source/cmStateDirectory.cxx
@@ -5,9 +5,10 @@
 
 #include <algorithm>
 #include <cassert>
-#include <iterator>
 #include <vector>
 
+#include <cm/iterator>
+
 #include "cmAlgorithms.h"
 #include "cmProperty.h"
 #include "cmPropertyMap.h"
@@ -177,7 +178,7 @@ cmStringRange GetPropertyContent(T const& content, U contentEndPosition)
 {
   auto end = content.begin() + contentEndPosition;
 
-  auto rbegin = cmMakeReverseIterator(end);
+  auto rbegin = cm::make_reverse_iterator(end);
   rbegin = std::find(rbegin, content.rend(), cmPropertySentinal);
 
   return cmMakeRange(rbegin.base(), end);
@@ -189,7 +190,7 @@ cmBacktraceRange GetPropertyBacktraces(T const& content, U const& backtraces,
 {
   auto entryEnd = content.begin() + contentEndPosition;
 
-  auto rbegin = cmMakeReverseIterator(entryEnd);
+  auto rbegin = cm::make_reverse_iterator(entryEnd);
   rbegin = std::find(rbegin, content.rend(), cmPropertySentinal);
 
   auto it = backtraces.begin() + std::distance(content.begin(), rbegin.base());
@@ -270,7 +271,7 @@ void cmStateDirectory::PrependIncludeDirectoriesEntry(
     this->Snapshot_.Position->IncludeDirectoryPosition;
 
   auto rend = this->DirectoryState->IncludeDirectories.rend();
-  auto rbegin = cmMakeReverseIterator(entryEnd);
+  auto rbegin = cm::make_reverse_iterator(entryEnd);
   rbegin = std::find(rbegin, rend, cmPropertySentinal);
 
   auto entryIt = rbegin.base();
@@ -440,7 +441,7 @@ void cmStateDirectory::PrependLinkDirectoriesEntry(
     this->Snapshot_.Position->LinkDirectoriesPosition;
 
   auto rend = this->DirectoryState->LinkDirectories.rend();
-  auto rbegin = cmMakeReverseIterator(entryEnd);
+  auto rbegin = cm::make_reverse_iterator(entryEnd);
   rbegin = std::find(rbegin, rend, cmPropertySentinal);
 
   auto entryIt = rbegin.base();