2 files changed, 10 insertions, 8 deletions
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index ae29a05..1638c64 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -168,6 +168,7 @@ public:
   cmStateEnums::TargetType TargetType;
   cmMakefile* Makefile;
   cmPropertyMap Properties;
+  std::set<std::string> SystemIncludeDirectories;
   std::vector<std::string> IncludeDirectoriesEntries;
   std::vector<cmListFileBacktrace> IncludeDirectoriesBacktraces;
   std::vector<std::string> CompileOptionsEntries;
@@ -373,7 +374,7 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
 
     {
       auto const& sysInc = impl->Makefile->GetSystemIncludeDirectories();
-      this->SystemIncludeDirectories.insert(sysInc.begin(), sysInc.end());
+      impl->SystemIncludeDirectories.insert(sysInc.begin(), sysInc.end());
     }
 
     CApp(impl->CompileOptionsEntries,
@@ -817,7 +818,12 @@ void cmTarget::AddLinkLibrary(cmMakefile& mf, std::string const& lib,
 
 void cmTarget::AddSystemIncludeDirectories(const std::set<std::string>& incs)
 {
-  this->SystemIncludeDirectories.insert(incs.begin(), incs.end());
+  impl->SystemIncludeDirectories.insert(incs.begin(), incs.end());
+}
+
+std::set<std::string> const& cmTarget::GetSystemIncludeDirectories() const
+{
+  return impl->SystemIncludeDirectories;
 }
 
 cmStringRange cmTarget::GetIncludeDirectoriesEntries() const
diff --git a/Source/cmTarget.h b/Source/cmTarget.h
index a1245a8..dca3dd4 100644
--- a/Source/cmTarget.h
+++ b/Source/cmTarget.h
@@ -250,11 +250,8 @@ public:
   std::string GetDebugGeneratorExpressions(const std::string& value,
                                            cmTargetLinkLibraryType llt) const;
 
-  void AddSystemIncludeDirectories(const std::set<std::string>& incs);
-  std::set<std::string> const& GetSystemIncludeDirectories() const
-  {
-    return this->SystemIncludeDirectories;
-  }
+  void AddSystemIncludeDirectories(std::set<std::string> const& incs);
+  std::set<std::string> const& GetSystemIncludeDirectories() const;
 
   cmStringRange GetIncludeDirectoriesEntries() const;
   cmBacktraceRange GetIncludeDirectoriesBacktraces() const;
@@ -304,7 +301,6 @@ private:
 
 private:
   bool IsGeneratorProvided;
-  std::set<std::string> SystemIncludeDirectories;
   std::set<BT<std::string>> Utilities;
   cmPolicies::PolicyMap PolicyMap;
   std::string Name;