泛型算法系列4:binary_search()

#include <numeric>#include <list>#include <functional>#include <iterator>#include <iostream>using namespace std;#include <algorithm>#include <vector>#include <assert.h> int main(){int ia[] = {29,23,20,22,17,15,26,51,19,12,35,40};sort( &ia[0], &ia[12] );bool found_it = binary_search( &ia[0], &ia[12], 18 );assert( found_it == false ); vector< int > vec( ia, ia+12 ); sort( vec.begin(), vec.end(), less<int>() ); found_it = binary_search( vec.begin(), vec.end(),26, less<int>() );assert( found_it == true );}/************************************************************************/template<class _FwdIt, class _Ty> inlinebool binary_search(_FwdIt _First, _FwdIt _Last, const _Ty& _Val){// test if _Val equivalent to some element, using operator<_First = std::lower_bound(_First, _Last, _Val);return (_First != _Last && !(_Val < *_First));}/************************************************************************//************************************************************************/ template<class _FwdIt, class _Ty, class _Pr> inlinebool binary_search(_FwdIt _First, _FwdIt _Last,const _Ty& _Val, _Pr _Pred){// test if _Val equivalent to some element, using _Pred_First = std::lower_bound(_First, _Last, _Val, _Pred);return (_First != _Last && !_Pred(_Val, *_First));}/************************************************************************/