cmFileTimeComparison: Replace anonymous private class with std::map

After the switch to `cmFileTime`, the anonymous private class of
`cmFileTimeComparison` held only a `std::map`.  This moves the
`std::map` to the `cmFileTimeComparison` class itself and removes the
instantiation of an anonymous private class.

Source/cmFileTimeComparison.cxx

@@ -6,71 +6,32 @@
 #include <unordered_map>
 #include <utility>
 
-class cmFileTimeComparisonInternal
-{
-public:
-  inline bool Load(std::string const& fname, cmFileTime& ftm);
-  inline bool FileTimeCompare(std::string const& f1, std::string const& f2,
-                              int* result);
-
-  bool FileTimesDiffer(std::string const& f1, std::string const& f2);
+cmFileTimeComparison::cmFileTimeComparison() = default;
 
-private:
-  typedef std::unordered_map<std::string, cmFileTime> FileStatsMap;
-  FileStatsMap Files;
-};
+cmFileTimeComparison::~cmFileTimeComparison() = default;
 
-bool cmFileTimeComparisonInternal::Load(std::string const& fname,
-                                        cmFileTime& ftm)
+bool cmFileTimeComparison::Load(std::string const& fileName,
+                                cmFileTime& fileTime)
 {
   // Use the stored time if available.
   {
-    auto fit = this->Files.find(fname);
-    if (fit != this->Files.end()) {
-      ftm = fit->second;
+    auto fit = this->FileTimes.find(fileName);
+    if (fit != this->FileTimes.end()) {
+      fileTime = fit->second;
       return true;
     }
   }
   // Read file time from OS
-  if (!ftm.Load(fname)) {
+  if (!fileTime.Load(fileName)) {
     return false;
   }
   // Store file time in cache
-  this->Files[fname] = ftm;
+  this->FileTimes[fileName] = fileTime;
   return true;
 }
 
-cmFileTimeComparison::cmFileTimeComparison()
-{
-  this->Internals = new cmFileTimeComparisonInternal;
-}
-
-cmFileTimeComparison::~cmFileTimeComparison()
-{
-  delete this->Internals;
-}
-
-bool cmFileTimeComparison::Load(std::string const& fileName,
-                                cmFileTime& fileTime)
-{
-  return this->Internals->Load(fileName, fileTime);
-}
-
 bool cmFileTimeComparison::FileTimeCompare(std::string const& f1,
                                            std::string const& f2, int* result)
-{
-  return this->Internals->FileTimeCompare(f1, f2, result);
-}
-
-bool cmFileTimeComparison::FileTimesDiffer(std::string const& f1,
-                                           std::string const& f2)
-{
-  return this->Internals->FileTimesDiffer(f1, f2);
-}
-
-bool cmFileTimeComparisonInternal::FileTimeCompare(std::string const& f1,
-                                                   std::string const& f2,
-                                                   int* result)
 {
   // Get the modification time for each file.
   cmFileTime ft1, ft2;
@@ -84,7 +45,7 @@ bool cmFileTimeComparisonInternal::FileTimeCompare(std::string const& f1,
   return false;
 }
 
-bool cmFileTimeComparisonInternal::FileTimesDiffer(std::string const& f1,
+bool cmFileTimeComparison::FileTimesDiffer(std::string const& f1,
                                            std::string const& f2)
 {
   // Get the modification time for each file.

Source/cmFileTimeComparison.h

@@ -7,8 +7,7 @@
 
 #include "cmFileTime.h"
 #include <string>
-
-class cmFileTimeComparisonInternal;
+#include <unordered_map>
 
 /** \class cmFileTimeComparison
  * \brief Caches file modification times in an internal map for fast lookups.
@@ -45,8 +44,9 @@ public:
    */
   bool FileTimesDiffer(std::string const& f1, std::string const& f2);
 
-protected:
-  cmFileTimeComparisonInternal* Internals;
+private:
+  typedef std::unordered_map<std::string, cmFileTime> FileTimeMap;
+  FileTimeMap FileTimes;
 };
 
 #endif