K>bool parse(int &r, const char *s)
K>{
K>    char *p;
K>    r = strtol(s, &p, 10);
K>    if (s == p || errno)
K>        return false;
K>    return *p == 0 || isspace((int)*p);
K>}

K>bool parse(double &r, const char *s)
K>{
K>    char *p;
K>    r = strtod(s, &p);
K>    if (s == p || errno)
K>        return false;
K>    return *p == 0 || isspace((int)*p);
K>}

K>// .....

K>template <class Result> Result
K>    lexical_cast(const char *str)
K>{
K>    if (!str)
K>        throw std::exception();

K>    Result r;
K>    if (!parse(r, str))
K>        throw std::exception();
K>    return r;
K>}
K>

//The following example uses numeric data in a string expression: void log_message(const std::string &);

void log_errno(int yoko)
{
    log_message("Error " + boost::lexical_cast<std::string>(yoko) + ": " + strerror(yoko));
}

K>bicycle:  0.135
K>crt::     0.682   (в 5 раз медленнее)
K>boost:    6.289   (в 46.5 раз медленнее велосипеда и в 10 раз медленнее crt)
K>

boost: 3.1415e+006: 3.027
crt: 3.1415e+006: 0.639
boost: 3.1415e+006: 3.042
crt: 3.1415e+006: 0.64
boost: 3.1415e+006: 3.042
crt: 3.1415e+006: 0.624

Level,Function Name,Inclusive Samples,Exclusive Samples,Inclusive Samples %,Exclusive Samples %,Module Name,
0,"lexical_cast_perf.exe","2,183",0,100.00,0.00,"",
0,"_mainCRTStartup","2,183",0,100.00,0.00,"lexical_cast_perf.exe",
4,"[4 rows folded ending in "__fltin2"]",323,12,14.80,0.55,"lexical_cast_perf.exe",
5,"___strgtold12_l",266,188,12.19,8.61,"lexical_cast_perf.exe",
6,"___mtold12",78,78,3.57,3.57,"lexical_cast_perf.exe",
1,"Unknown Frame(s)","1,811",0,82.96,0.00,"UNKNOWN",
2,"_main","1,677",51,76.82,2.34,"lexical_cast_perf.exe",
3,"__Mtxunlock",78,5,3.57,0.23,"lexical_cast_perf.exe",
4,"[ntdll.dll]",67,67,3.07,3.07,"ntdll.dll",
4,"[2 rows folded ending in "_malloc"]",89,12,4.08,0.55,"lexical_cast_perf.exe",
5,"[ntdll.dll]",77,23,3.53,1.05,"ntdll.dll",
4,"[2 rows folded ending in "__Mtxlock"]",93,6,4.26,0.27,"lexical_cast_perf.exe",
5,"[ntdll.dll]",87,87,3.99,3.99,"ntdll.dll",
3,"std::ios_base::_Ios_base_dtor(class std::ios_base *)",106,4,4.86,0.18,"lexical_cast_perf.exe",
4,"std::locale::`scalar deleting destructor'(unsigned int)",96,10,4.40,0.46,"lexical_cast_perf.exe",
4,"[2 rows folded ending in "__Mtxdst"]",79,2,3.62,0.09,"lexical_cast_perf.exe",
5,"[ntdll.dll]",77,15,3.53,0.69,"ntdll.dll",
3,"std::_Mutex::_Mutex(void)",145,7,6.64,0.32,"lexical_cast_perf.exe",
5,"[2 rows folded ending in "[ntdll.dll]"]",74,4,3.39,0.18,"ntdll.dll",
6,"[ntdll.dll]",70,9,3.21,0.41,"ntdll.dll",
3,"std::basic_istream<char,struct std::char_traits<char> >::operator>>(double &)",801,36,36.69,1.65,"lexical_cast_perf.exe",
4,"std::num_get<char,class std::istreambuf_iterator<char,struct std::char_traits<char> > >::do_get(class std::istreambuf_iterator<char,struct std::char_traits<char> >,class std::istreambuf_iterator<char,struct std::char_traits<char> >,class std::ios_base &,int &,double &)const ",650,11,29.78,0.50,"lexical_cast_perf.exe",
5,"std::num_get<char,class std::istreambuf_iterator<char,struct std::char_traits<char> > >::_Getffld(char *,class std::istreambuf_iterator<char,struct std::char_traits<char> > &,class std::istreambuf_iterator<char,struct std::char_traits<char> > &,class std::locale const &)const ",168,98,7.70,4.49,"lexical_cast_perf.exe",
6,"[2 rows folded ending in "_strtod"]",335,4,15.35,0.18,"lexical_cast_perf.exe",
8,"[2 rows folded ending in "__fltin2"]",294,8,13.47,0.37,"lexical_cast_perf.exe",
9,"___strgtold12_l",250,164,11.45,7.51,"lexical_cast_perf.exe",
10,"___mtold12",84,83,3.85,3.80,"lexical_cast_perf.exe",