make printer functions virtual
diff --git a/tinyxml2.h b/tinyxml2.h
index 3c702ec..b185fa1 100755
--- a/tinyxml2.h
+++ b/tinyxml2.h
@@ -2327,10 +2327,11 @@
 	    the space and tabs used. A PrintSpace() override should call Print().

 	*/

     virtual void PrintSpace( int depth );

-    void Print( const char* format, ... );

-    void Write( const char* data, size_t size );

-    inline void Write( const char* data )           { Write( data, strlen( data ) ); }

-    void Putc( char ch );

+    virtual void Print( const char* format, ... );

+    virtual void Write( const char* data, size_t size );

+    virtual void Putc( char ch );

+

+    inline void Write(const char* data) { Write(data, strlen(data)); }

 

     void SealElementIfJustOpened();

     bool _elementJustOpened;