Make several methods static.
diff --git a/include/json/value.h b/include/json/value.h
index 06a6c0c..b94aeec 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -720,7 +720,7 @@
                     const InArgs& in,
                     InArgs::const_iterator& itInArg,
                     PathArgument::Kind kind);
-  void invalidPath(const JSONCPP_STRING& path, int location);
+  static void invalidPath(const JSONCPP_STRING& path, int location);
 
   Args args_;
 };
diff --git a/include/json/writer.h b/include/json/writer.h
index 7c9ae21..c92d26b 100644
--- a/include/json/writer.h
+++ b/include/json/writer.h
@@ -249,7 +249,7 @@
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
+  static bool hasCommentForValue(const Value& value);
   static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
 
   typedef std::vector<JSONCPP_STRING> ChildValues;
@@ -323,7 +323,7 @@
   void unindent();
   void writeCommentBeforeValue(const Value& root);
   void writeCommentAfterValueOnSameLine(const Value& root);
-  bool hasCommentForValue(const Value& value);
+  static bool hasCommentForValue(const Value& value);
   static JSONCPP_STRING normalizeEOL(const JSONCPP_STRING& text);
 
   typedef std::vector<JSONCPP_STRING> ChildValues;