From 98c5c90361f89f810cdd6fb233f3e822b638f143 Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Sat, 16 May 2015 05:33:25 +0200
Subject: [PATCH] cmDefinitions: Centralize knowledge of iterator type.

Currently we process a list of definitions, but that will change.
---
 Source/cmDefinitions.cxx | 33 ++++++++++++++-------------------
 Source/cmDefinitions.h   | 12 +++++-------
 2 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/Source/cmDefinitions.cxx b/Source/cmDefinitions.cxx
index 581f259fc..6fcc002b6 100644
--- a/Source/cmDefinitions.cxx
+++ b/Source/cmDefinitions.cxx
@@ -18,32 +18,29 @@ cmDefinitions::Def cmDefinitions::NoDef;
 
 //----------------------------------------------------------------------------
 cmDefinitions::Def const& cmDefinitions::GetInternal(
-  const std::string& key,
-  std::list<cmDefinitions>::reverse_iterator rbegin,
-  std::list<cmDefinitions>::reverse_iterator rend)
+  const std::string& key, StackIter begin, StackIter end)
 {
-  assert(rbegin != rend);
-  MapType::const_iterator i = rbegin->Map.find(key);
-  if (i != rbegin->Map.end())
+  assert(begin != end);
+  MapType::const_iterator i = begin->Map.find(key);
+  if (i != begin->Map.end())
     {
     return i->second;
     }
-  std::list<cmDefinitions>::reverse_iterator rit = rbegin;
-  ++rit;
-  if (rit == rend)
+  StackIter it = begin;
+  ++it;
+  if (it == end)
     {
     return cmDefinitions::NoDef;
     }
-  Def const& def = cmDefinitions::GetInternal(key, rit, rend);
-  return rbegin->Map.insert(MapType::value_type(key, def)).first->second;
+  Def const& def = cmDefinitions::GetInternal(key, it, end);
+  return begin->Map.insert(MapType::value_type(key, def)).first->second;
 }
 
 //----------------------------------------------------------------------------
 const char* cmDefinitions::Get(const std::string& key,
-    std::list<cmDefinitions>::reverse_iterator rbegin,
-    std::list<cmDefinitions>::reverse_iterator rend)
+    StackIter begin, StackIter end)
 {
-  Def const& def = cmDefinitions::GetInternal(key, rbegin, rend);
+  Def const& def = cmDefinitions::GetInternal(key, begin, end);
   return def.Exists? def.c_str() : 0;
 }
 
@@ -77,14 +74,12 @@ std::vector<std::string> cmDefinitions::LocalKeys() const
 }
 
 //----------------------------------------------------------------------------
-cmDefinitions cmDefinitions::MakeClosure(
-    std::list<cmDefinitions>::const_reverse_iterator rbegin,
-    std::list<cmDefinitions>::const_reverse_iterator rend)
+cmDefinitions cmDefinitions::MakeClosure(StackConstIter begin,
+                                         StackConstIter end)
 {
   cmDefinitions closure;
   std::set<std::string> undefined;
-  for (std::list<cmDefinitions>::const_reverse_iterator it = rbegin;
-       it != rend; ++it)
+  for (StackConstIter it = begin; it != end; ++it)
     {
     // Consider local definitions.
     for(MapType::const_iterator mi = it->Map.begin();
diff --git a/Source/cmDefinitions.h b/Source/cmDefinitions.h
index e762b4128..b95ae6ba5 100644
--- a/Source/cmDefinitions.h
+++ b/Source/cmDefinitions.h
@@ -28,12 +28,13 @@
  */
 class cmDefinitions
 {
+  typedef std::list<cmDefinitions>::reverse_iterator StackIter;
+  typedef std::list<cmDefinitions>::const_reverse_iterator StackConstIter;
 public:
   /** Get the value associated with a key; null if none.
       Store the result locally if it came from a parent.  */
   static const char* Get(const std::string& key,
-                         std::list<cmDefinitions>::reverse_iterator rbegin,
-                         std::list<cmDefinitions>::reverse_iterator rend);
+                         StackIter begin, StackIter end);
 
   /** Set (or unset if null) a value associated with a key.  */
   void Set(const std::string& key, const char* value);
@@ -46,9 +47,7 @@ public:
   std::vector<std::string>
   ClosureKeys(std::set<std::string>& bound) const;
 
-  static cmDefinitions MakeClosure(
-      std::list<cmDefinitions>::const_reverse_iterator rbegin,
-      std::list<cmDefinitions>::const_reverse_iterator rend);
+  static cmDefinitions MakeClosure(StackConstIter begin, StackConstIter end);
 
 private:
   // String with existence boolean.
@@ -74,8 +73,7 @@ private:
   MapType Map;
 
   static Def const& GetInternal(const std::string& key,
-    std::list<cmDefinitions>::reverse_iterator rbegin,
-    std::list<cmDefinitions>::reverse_iterator rend);
+    StackIter begin, StackIter end);
 };
 
 #endif