template<typename,typename=int,typename=int>struct basic_string;
typedef basic_string<char> string;
template<typename aT,typename,typename oc>
struct basic_string
{
int us;
basic_string(const aT*,const oc&a=int());
int _S_construct();
int _S_construct(int);
_S_construct(); };
template<typename _CharT,typename _Traits,typename _Alloc>
basic_string<_CharT,_Traits,_Alloc>::basic_string(const _CharT*,const _Alloc&)
:us(_S_construct)
{string a;}
struct runtime_error{runtime_error(string);};
struct system_error:runtime_error{ system_error():time_error(""