cmPolicies: Implement abstraction for PolicyMap.

Hide the detail that it is a std::map.

Source/cmMakefile.cxx

@@ -569,7 +569,7 @@ cmMakefile::IncludeScope::~IncludeScope()
     // one we pushed above.  If the entry is empty, then the included
     // script did not set any policies that might affect the includer so
     // we do not need to enforce the policy.
-    if(this->CheckCMP0011 && this->Makefile->PolicyStack.back().empty())
+    if(this->CheckCMP0011 && this->Makefile->PolicyStack.back().IsEmpty())
       {
       this->CheckCMP0011 = false;
       }
@@ -4772,10 +4772,9 @@ cmMakefile::GetPolicyStatusInternal(cmPolicies::PolicyID id) const
   for(PolicyStackType::const_reverse_iterator psi = this->PolicyStack.rbegin();
       psi != this->PolicyStack.rend(); ++psi)
     {
-    PolicyStackEntry::const_iterator pse = psi->find(id);
+    if(psi->IsDefined(id))
-    if(pse != psi->end())
       {
-      return pse->second;
+      return psi->Get(id);
       }
     }
 
@@ -4840,7 +4839,7 @@ bool cmMakefile::SetPolicy(cmPolicies::PolicyID id,
   for(PolicyStackType::reverse_iterator psi = this->PolicyStack.rbegin();
       previous_was_weak && psi != this->PolicyStack.rend(); ++psi)
     {
-    (*psi)[id] = status;
+    psi->Set(id, status);
     previous_was_weak = psi->Weak;
     }
 
@@ -4960,7 +4959,7 @@ void cmMakefile::RecordPolicies(cmPolicies::PolicyMap& pm)
   for(PolicyID pid = cmPolicies::CMP0000;
       pid != cmPolicies::CMPCOUNT; pid = PolicyID(pid+1))
     {
-    pm[pid] = this->GetPolicyStatus(pid);
+    pm.Set(pid, this->GetPolicyStatus(pid));
     }
 }
 

Source/cmPolicies.cxx

@@ -342,3 +342,25 @@ cmPolicies::GetRequiredAlwaysPolicyError(cmPolicies::PolicyID id)
     << "Run cmake --help-policy " << pid << " for more information.";
   return e.str();
 }
+
+cmPolicies::PolicyStatus
+cmPolicies::PolicyMap::Get(cmPolicies::PolicyID id) const
+{
+  return this->find(id)->second;
+}
+
+void cmPolicies::PolicyMap::Set(cmPolicies::PolicyID id,
+                                cmPolicies::PolicyStatus status)
+{
+  (*this)[id] = status;
+}
+
+bool cmPolicies::PolicyMap::IsDefined(cmPolicies::PolicyID id) const
+{
+  return this->find(id) != this->end();
+}
+
+bool cmPolicies::PolicyMap::IsEmpty() const
+{
+  return this->empty();
+}

Source/cmPolicies.h

@@ -268,7 +268,13 @@ public:
   static std::string GetRequiredAlwaysPolicyError(cmPolicies::PolicyID id);
 
   /** Represent a set of policy values.  */
-  typedef std::map<PolicyID, PolicyStatus> PolicyMap;
+  struct PolicyMap : private std::map<PolicyID, PolicyStatus>
+  {
+    PolicyStatus Get(PolicyID id) const;
+    void Set(PolicyID id, PolicyStatus status);
+    bool IsDefined(PolicyID id) const;
+    bool IsEmpty() const;
+  };
 };
 
 #endif