template <class _Tp>
struct _Identity : public unary_function<_Tp,_Tp> {
const _Tp& operator()(const _Tp& __x) const { return __x; }
};
template <class _Tp> struct identity : public _Identity<_Tp> {};
//楠岃瘉妯℃澘鍙傛暟鏄笉鏄竴涓嚱鏁板璞＄被鍨?BR>
template <class _Pair>
struct _Select1st : public unary_function<_Pair, typename _Pair::first_type> {
const typename _Pair::first_type& operator()(const _Pair& __x) const {
return __x.first;
}
};
template <class _Pair>
struct _Select2nd : public unary_function<_Pair, typename _Pair::second_type>
{
const typename _Pair::second_type& operator()(const _Pair& __x) const {
return __x.second;
}
};
template <class _Pair> struct select1st : public _Select1st<_Pair> {};
template <class _Pair> struct select2nd : public _Select2nd<_Pair> {};
//蹇界暐妯℃澘鍙傛暟涓簆air綾誨瀷鎵鍖呭惈鐨勭浉搴斿弬鏁?絎竴涓弬鏁板拰絎簩涓弬鏁?
template <class _Arg1, class _Arg2>
struct _Project1st : public binary_function<_Arg1, _Arg2, _Arg1> {
_Arg1 operator()(const _Arg1& __x, const _Arg2&) const { return __x; }
};
template <class _Arg1, class _Arg2>
struct _Project2nd : public binary_function<_Arg1, _Arg2, _Arg2> {
_Arg2 operator()(const _Arg1&, const _Arg2& __y) const { return __y; }
};
template <class _Arg1, class _Arg2>
struct project1st : public _Project1st<_Arg1, _Arg2> {};
template <class _Arg1, class _Arg2>
struct project2nd : public _Project2nd<_Arg1, _Arg2> {};
//蹇界暐璋冪敤榪愮畻絎︽椂鐩稿簲鐨勫弬鏁?/P>
template <class _Result>
struct _Constant_void_fun {
typedef _Result result_type;
result_type _M_val;
_Constant_void_fun(const result_type& __v) : _M_val(__v) {}
const result_type& operator() const { return _M_val; }
};
template <class _Result, class _Argument>
struct _Constant_unary_fun {
typedef _Argument argument_type;
typedef _Result result_type;
result_type _M_val;
_Constant_unary_fun(const result_type& __v) : _M_val(__v) {}
const result_type& operator()(const _Argument&) const { return _M_val; }
};
template <class _Result, class _Arg1, class _Arg2>
struct _Constant_binary_fun {
typedef _Arg1 first_argument_type;
typedef _Arg2 second_argument_type;
typedef _Result result_type;
_Result _M_val;
_Constant_binary_fun(const _Result& __v) : _M_val(__v) {}
const result_type& operator()(const _Arg1&, const _Arg2&) const {
return _M_val;
}
};
//榪斿洖涓涓櫘閫氬彉閲忕殑const鍓湰,鏃犺鍙傛暟涓轟綍,鍙繑鍥炲悓涓涓肩殑鍑芥暟瀵硅薄
template <class _Result>
struct constant_void_fun : public _Constant_void_fun<_Result> {
constant_void_fun(const _Result& __v) : _Constant_void_fun<_Result>(__v) {}
};
template <class _Result,
class _Argument __STL_DEPENDENT_DEFAULT_TMPL(_Result)>
struct constant_unary_fun : public _Constant_unary_fun<_Result, _Argument>
{
constant_unary_fun(const _Result& __v)
: _Constant_unary_fun<_Result, _Argument>(__v) {}
};
template <class _Result,
class _Arg1 __STL_DEPENDENT_DEFAULT_TMPL(_Result),
class _Arg2 __STL_DEPENDENT_DEFAULT_TMPL(_Arg1)>
struct constant_binary_fun
: public _Constant_binary_fun<_Result, _Arg1, _Arg2>
{
constant_binary_fun(const _Result& __v)
: _Constant_binary_fun<_Result, _Arg1, _Arg2>(__v) {}
};
//__STL_DEPENDENT_DEFAULT_TMPL 鏄竴涓畯錛屾剰鎬濇槸濡傛灉緙栬瘧鍣ㄤ笉鏀寔榛樿妯℃澘鍙傛暟錛屽垯浣跨敤涓婁竴綰фā鏉垮弬鏁?BR>
template <class _Result>
inline constant_void_fun<_Result> constant0(const _Result& __val)
{
return constant_void_fun<_Result>(__val);
}
template <class _Result>
inline constant_unary_fun<_Result,_Result> constant1(const _Result& __val)
{
return constant_unary_fun<_Result,_Result>(__val);
}
template <class _Result>
inline constant_binary_fun<_Result,_Result,_Result>
constant2(const _Result& __val)
{
return constant_binary_fun<_Result,_Result,_Result>(__val);
}
//鍑芥暟榪斿洖涓涓彧榪斿洖甯擱噺鍜岃緭鍏ュ弬鏁版棤鍏崇殑鍑芥暟瀵硅薄
]]>