泛型算法系列2:adjacent_difference()

//adjacent_difference need to include this#include <numeric>#include <list>#include <functional>#include <iterator>#include <iostream>using namespace std;int main(){int ia[] = { 1, 1, 2, 3, 5, 8 };list<int> ilist(ia, ia + 6);list<int> ilist_result(ilist.size()); adjacent_difference(ilist.begin(), ilist.end(), ilist_result.begin() ); // generates output:// 1 0 1 1 2 3copy( ilist_result.begin(), ilist_result.end(), ostream_iterator<int>(cout," "));cout << endl; adjacent_difference( ilist.begin(), ilist.end(), ilist_result.begin(),plus<int>() );// generates output: // 1 1 2 6 15 40 copy( ilist_result.begin(), ilist_result.end(), ostream_iterator<int>(cout," ")); cout << endl;return 0;}/************************************************************************/①template<class _InIt, class _OutIt, class _Ty, class _InOutItCat>inline_OutIt _Adjacent_difference(_InIt _First, _InIt _Last,_OutIt _Dest, _Ty *, _InOutItCat, _Range_checked_iterator_tag){// compute adjacent differences into _Dest_Ty _Val = *_First;for (*_Dest = _Val; ++_First != _Last; ){// compute another difference_Ty _Tmp = *_First;*++_Dest = _Tmp - _Val;_Val = _Tmp;}return (++_Dest);}/************************************************************************//************************************************************************/ ②template<class _InIt, class _OutIt, class _Fn2, class _Ty, class _InOutItCat>inline_OutIt _Adjacent_difference(_InIt _First, _InIt _Last,_OutIt _Dest, _Fn2 _Func,_Ty *, _InOutItCat, _Range_checked_iterator_tag){// compute adjacent differences into _Dest, using _Func_Ty _Val = *_First;for (*_Dest = _Val; ++_First != _Last; ){// compute another difference_Ty _Tmp = *_First;*++_Dest = _Func(_Tmp, _Val);_Val = _Tmp;}return (++_Dest);}/************************************************************************/