void read ( const FileNode& node, MyData& x, const MyData& default_value = MyData ( ) ) { if ( node.empty ( ) ) { x = default_value; } else { x.read ( node ); } }
static void read(const FileNode& node, MyData& x, const MyData& default_value = MyData()){ if(node.empty()) x = default_value; else x.read(node); }