int str2x(const std::string & str, unsigned long long & x);
//-----------------------------------------------------------------------------
const std::string & x2str(unsigned x, std::string & s);
+const std::string & x2str(unsigned long x, std::string & s);
const std::string & x2str(unsigned long long x, std::string & s);
//-----------------------------------------------------------------------------
char * stg_strptime(const char *, const char *, struct tm *);