一、equal
作用：判断[first,last)区间两个元素是否相同，第二个迭代器多出来的元素不予考虑。
template <class _InputIter1, class _InputIter2>//版本1 inline bool equal(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2) { for ( ; __first1 != __last1; ++__first1, ++__first2)//遍历区间[first，last)元素 if (*__first1 != *__first2)//只有有一个不相等返回false return false; return true; } template <class _InputIter1, class _InputIter2, class _BinaryPredicate>//版本2 inline bool equal(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2, _BinaryPredicate __binary_pred) { for ( ; __first1 != __last1; ++__first1, ++__first2) if (!__binary_pred(*__first1, *__first2))//两个元素执行二元操作符 return false; return true; } 二、fill作用：将指定区间元素改为新值
template <class _ForwardIter, class _Tp> void fill(_ForwardIter __first, _ForwardIter __last, const _Tp& __value) { for ( ; __first != __last; ++__first)//遍历整个区间 *__first = __value;//指定新值 } 三、fill_n作用：将指定区间前n个元素改为新值
template <class _OutputIter, class _Size, class _Tp> _OutputIter fill_n(_OutputIter __first, _Size __n, const _Tp& __value) { for ( ; __n > 0; --__n, ++__first) *__first = __value; return __first; }问题：如果n大于元素区间个数？采用inserter（）修改： int a[3] = {0,1,2}; vector<int> iv (a,a+3);//0,1,2 fill_n(inserter(iv,iv.begin()),5,1);//1,1,1,1,1,0,1,2四、iter_swap作用：将两个迭代器所指对象调换。
template <class _ForwardIter1, class _ForwardIter2, class _Tp> inline void __iter_swap(_ForwardIter1 __a, _ForwardIter2 __b, _Tp*) { _Tp __tmp = *__a; *__a = *__b; *__b = __tmp; } template <class _ForwardIter1, class _ForwardIter2> inline void iter_swap(_ForwardIter1 __a, _ForwardIter2 __b) { __iter_swap(__a, __b, __VALUE_TYPE(__a)); }五、lexicographical_compare作用：以字典排序方式对两个序列进行比较，第一个元素小于第二个元素返回true。
template <class _InputIter1, class _InputIter2> bool lexicographical_compare(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2, _InputIter2 __last2) { for ( ; __first1 != __last1 && __first2 != __last2//两组元素一一比较，除非长度不相同 ; ++__first1, ++__first2) { if (*__first1 < *__first2) return true; if (*__first2 < *__first1) return false; } return __first1 == __last1 && __first2 != __last2;//第二组还有元素 } template <class _InputIter1, class _InputIter2, class _Compare> bool lexicographical_compare(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2, _InputIter2 __last2, _Compare __comp) { for ( ; __first1 != __last1 && __first2 != __last2 ; ++__first1, ++__first2) { if (__comp(*__first1, *__first2)) return true; if (__comp(*__first2, *__first1)) return false; } return __first1 == __last1 && __first2 != __last2; }六、max
作用：取两个元素最大值
template <class _Tp> inline const _Tp& max(const _Tp& __a, const _Tp& __b) { return __a < __b ? __b : __a; } template <class _Tp, class _Compare> inline const _Tp& max(const _Tp& __a, const _Tp& __b, _Compare __comp) { return __comp(__a, __b) ? __b : __a; }七、min作用：取两个元素最小值
template <class _Tp> inline const _Tp& min(const _Tp& __a, const _Tp& __b) { return __b < __a ? __b : __a; } template <class _Tp, class _Compare> inline const _Tp& min(const _Tp& __a, const _Tp& __b, _Compare __comp) { return __comp(__b, __a) ? __b : __a; }八、mismatch作用：用来比较两个序列，指出两者之间第一个不匹配点
template <class _InputIter1, class _InputIter2> pair<_InputIter1, _InputIter2> mismatch(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2) { while (__first1 != __last1 && *__first1 == *__first2) { ++__first1; ++__first2; } return pair<_InputIter1, _InputIter2>(__first1, __first2);//返回pair类型，first1指向第一个序列不匹配点，first2指向第二个序列不匹配点 } template <class _InputIter1, class _InputIter2, class _BinaryPredicate> pair<_InputIter1, _InputIter2> mismatch(_InputIter1 __first1, _InputIter1 __last1, _InputIter2 __first2, _BinaryPredicate __binary_pred) { while (__first1 != __last1 && __binary_pred(*__first1, *__first2)) { ++__first1; ++__first2; } return pair<_InputIter1, _InputIter2>(__first1, __first2); } 九、copy作用：拷贝复制
template <class _InputIter, class _OutputIter, class _Distance> inline _OutputIter __copy(_InputIter __first, _InputIter __last, _OutputIter __result, input_iterator_tag, _Distance*) { for ( ; __first != __last; ++__result, ++__first) *__result = *__first;//赋值操作 return __result; } template <class _RandomAccessIter, class _OutputIter, class _Distance> inline _OutputIter __copy(_RandomAccessIter __first, _RandomAccessIter __last, _OutputIter __result, random_access_iterator_tag, _Distance*) { for (_Distance __n = __last - __first; __n > 0; --__n) {//确定拷贝的个数 *__result = *__first; ++__first; ++__result; } return __result; } template <class _InputIter, class _OutputIter, class _BoolType> struct __copy_dispatch {//完全泛化版本 static _OutputIter copy(_InputIter __first, _InputIter __last, _OutputIter __result) { typedef typename iterator_traits<_InputIter>::iterator_category _Category; typedef typename iterator_traits<_InputIter>::difference_type _Distance; return __copy(__first, __last, __result, _Category(), (_Distance*) 0); } }; template <class _Tp> struct __copy_dispatch<_Tp*, _Tp*, __true_type>//偏特化版本 { static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) { return __copy_trivial(__first, __last, __result); } }; template <class _Tp> struct __copy_dispatch<const _Tp*, _Tp*, __true_type>//偏特化版本 { static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) { return __copy_trivial(__first, __last, __result); } }; template <class _InputIter, class _OutputIter> inline _OutputIter copy(_InputIter __first, _InputIter __last, _OutputIter __result) { typedef typename iterator_traits<_InputIter>::value_type _Tp; typedef typename __type_traits<_Tp>::has_trivial_assignment_operator _Trivial; return __copy_dispatch<_InputIter, _OutputIter, _Trivial> ::copy(__first, __last, __result); } template <class _BidirectionalIter1, class _BidirectionalIter2, class _Distance> inline _BidirectionalIter2 __copy_backward(_BidirectionalIter1 __first, _BidirectionalIter1 __last, _BidirectionalIter2 __result, bidirectional_iterator_tag, _Distance*) { while (__first != __last) *--__result = *--__last; return __result; } template <class _RandomAccessIter, class _BidirectionalIter, class _Distance> inline _BidirectionalIter __copy_backward(_RandomAccessIter __first, _RandomAccessIter __last, _BidirectionalIter __result, random_access_iterator_tag, _Distance*) { for (_Distance __n = __last - __first; __n > 0; --__n) *--__result = *--__last; return __result; } template <class _BidirectionalIter1, class _BidirectionalIter2, class _BoolType> struct __copy_backward_dispatch { typedef typename iterator_traits<_BidirectionalIter1>::iterator_category _Cat; typedef typename iterator_traits<_BidirectionalIter1>::difference_type _Distance; static _BidirectionalIter2 copy(_BidirectionalIter1 __first, _BidirectionalIter1 __last, _BidirectionalIter2 __result) { return __copy_backward(__first, __last, __result, _Cat(), (_Distance*) 0); } }; template <class _Tp> struct __copy_backward_dispatch<_Tp*, _Tp*, __true_type> { static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) { const ptrdiff_t _Num = __last - __first; memmove(__result - _Num, __first, sizeof(_Tp) * _Num); return __result - _Num; } }; template <class _Tp> struct __copy_backward_dispatch<const _Tp*, _Tp*, __true_type> { static _Tp* copy(const _Tp* __first, const _Tp* __last, _Tp* __result) { return __copy_backward_dispatch<_Tp*, _Tp*, __true_type> ::copy(__first, __last, __result); } }; template <class _BI1, class _BI2> inline _BI2 copy_backward(_BI1 __first, _BI1 __last, _BI2 __result) { __STL_REQUIRES(_BI1, _BidirectionalIterator); __STL_REQUIRES(_BI2, _Mutable_BidirectionalIterator); __STL_CONVERTIBLE(typename iterator_traits<_BI1>::value_type, typename iterator_traits<_BI2>::value_type); typedef typename __type_traits<typename iterator_traits<_BI2>::value_type> ::has_trivial_assignment_operator _Trivial; return __copy_backward_dispatch<_BI1, _BI2, _Trivial> ::copy(__first, __last, __result); } template <class _InputIter, class _Size, class _OutputIter> pair<_InputIter, _OutputIter> __copy_n(_InputIter __first, _Size __count,//拷贝n个元素 _OutputIter __result, input_iterator_tag) { for ( ; __count > 0; --__count) { *__result = *__first; ++__first; ++__result; } return pair<_InputIter, _OutputIter>(__first, __result); } template <class _RAIter, class _Size, class _OutputIter> inline pair<_RAIter, _OutputIter> __copy_n(_RAIter __first, _Size __count, _OutputIter __result, random_access_iterator_tag) { _RAIter __last = __first + __count; return pair<_RAIter, _OutputIter>(__last, copy(__first, __last, __result)); } template <class _InputIter, class _Size, class _OutputIter> inline pair<_InputIter, _OutputIter> __copy_n(_InputIter __first, _Size __count, _OutputIter __result) { return __copy_n(__first, __count, __result, __ITERATOR_CATEGORY(__first)); } template <class _InputIter, class _Size, class _OutputIter> inline pair<_InputIter, _OutputIter> copy_n(_InputIter __first, _Size __count, _OutputIter __result) { return __copy_n(__first, __count, __result); }
