- LexicalConverter(const Fmt &f): fmt(f) { }
- LexicalConverter(const std::string &s, const Fmt &f): fmt(f), buf(s) { }
+ LexicalConverter(const Fmt &f): fmt(f), filled(false) { }
+ LexicalConverter(const std::string &s, const Fmt &f): fmt(f), filled(true), buf(s) { }