Very poor boost::lexical_cast performance

Question

Windows XP SP3. Core 2 Duo 2.0 GHz. I\'m finding the boost::lexical_cast performance to be extremely slow. Wanted to find out ways to speed up the code. Using /O2 optimizati

Answer 1

I use this very fast solution for POD types...

namespace DATATYPES {

    typedef std::string   TString;
    typedef char*         TCString;
    typedef double        TDouble;
    typedef long          THuge;
    typedef unsigned long TUHuge;
};

namespace boost {

template
inline const DATATYPES::TString lexical_castNumericToString(

                                const TYPE& arg, 
                                const DATATYPES::TCString fmt) {

    enum { MAX_SIZE = ( std::numeric_limits::digits10 + 1 )  // sign
                                                            + 1 }; // null
    char buffer[MAX_SIZE] = { 0 };

    if (sprintf(buffer, fmt, arg) < 0) {
        throw_exception(bad_lexical_cast(typeid(TYPE),
                                         typeid(DATATYPES::TString)));
    }
    return ( DATATYPES::TString(buffer) );
}

template
inline const TYPE lexical_castStringToNumeric(const DATATYPES::TString& arg) {

    DATATYPES::TCString end = 0;
    DATATYPES::TDouble result = std::strtod(arg.c_str(), &end);

    if (not end or *end not_eq 0) {
        throw_exception(bad_lexical_cast(typeid(DATATYPES::TString),
                                         typeid(TYPE)));
    }
    return TYPE(result);
}

template<>
inline DATATYPES::THuge lexical_cast(const DATATYPES::TString& arg) {
    return (lexical_castStringToNumeric(arg));
}

template<>
inline DATATYPES::TString lexical_cast(const DATATYPES::THuge& arg) {
    return (lexical_castNumericToString(arg,"%li"));
}

template<>
inline DATATYPES::TUHuge lexical_cast(const DATATYPES::TString& arg) {
    return (lexical_castStringToNumeric(arg));
}

template<>
inline DATATYPES::TString lexical_cast(const DATATYPES::TUHuge& arg) {
    return (lexical_castNumericToString(arg,"%lu"));
}

template<>
inline DATATYPES::TDouble lexical_cast(const DATATYPES::TString& arg) {
    return (lexical_castStringToNumeric(arg));
}

template<>
inline DATATYPES::TString lexical_cast(const DATATYPES::TDouble& arg) {
    return (lexical_castNumericToString(arg,"%f"));
}

} // end namespace boost