binary_negate Class

提供消除一个指定的二进制函数的返回值的成员函数的模板选件类。

template<class Operation>
   class binary_negate
      : public binary_function <
         typename Operation::first_argument_type,
         typename Operation::second_argument_type, 
         bool> 
   {
   public:
   explicit binary_negate(
      const Operation& _Func
   );
   bool operator()(
      const typename Operation::first_argument_type& _Left,
      const typename Operation::second_argument_type& _Right
   ) const;
   };

参数

• _Func
  将否定的二进制功能。

• _Left
  将否定的二进制左操作数。

• _Right
  将否定的二进制功能的右操作数。

返回值

二进制功能求反。

备注

模板选件类存储二进制函数对象_Func的副本。 它定义其成员函数 operator() 成返回 !_Func*(_Left，_Right)。*

直接很少使用 binary_negate 构造函数。 helper函数 not2 通常首选的声明和使用 binary_negator 适配器性质。

示例

// functional_binary_negate.cpp
// compile with: /EHsc
#define _CRT_RAND_S
#include <stdlib.h>

#include <vector>
#include <algorithm>
#include <functional>
#include <iostream>

int main( )
{
   using namespace std;
   vector <unsigned int> v1;
   vector <unsigned int>::iterator Iter1;

   unsigned int i;
   v1.push_back( 6262 );
   v1.push_back( 6262 );
   unsigned int randVal = 0;
   for ( i = 0 ; i < 5 ; i++ )
   {
      rand_s(&randVal);
      v1.push_back( randVal );
   }

   cout << "Original vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;

   // To sort in ascending order,
   // use default binary predicate less<unsigned int>( )
   sort( v1.begin( ), v1.end( ) );
   cout << "Sorted vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;

   // To sort in descending order,
   // use the binary_negate function
   sort( v1.begin( ), v1.end( ),
   binary_negate<less<unsigned int> >(less<unsigned int>( ) ) );

   // The helper function not2 could also have been used
   // in the above line and is usually preferred for convenience
   // sort( v1.begin( ), v1.end( ), not2(less<unsigned int>( ) ) );

   cout << "Resorted vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
}

要求

标头: <functional>

std

请参见

参考

线程安全性对标准C++库中

标准模板库