function::swap

交換兩個可呼叫的物件。

void swap(function& right);

參數

• right
  要交換的函式物件。

備註

成員函式切換 *this 和 right的目標物件。 它在常數時間這樣做並不會擲回例外狀況。

範例

// std_tr1__functional__function_swap.cpp 
// compile with: /EHsc 
#include <functional> 
#include <iostream> 
 
int neg(int val) 
    { 
    return (-val); 
    } 
 
int main() 
    { 
    std::function<int (int)> fn0(neg); 
    std::cout << std::boolalpha << "empty == " << !fn0 << std::endl; 
    std::cout << "val == " << fn0(3) << std::endl; 
 
    std::function<int (int)> fn1; 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
    std::cout << std::endl; 
 
    fn0.swap(fn1); 
    std::cout << std::boolalpha << "empty == " << !fn0 << std::endl; 
    std::cout << std::boolalpha << "empty == " << !fn1 << std::endl; 
    std::cout << "val == " << fn1(3) << std::endl; 
 
    return (0); 
    } 
 

需求

標題: <functional>

命名空間: std

請參閱

參考

function Class

function::operator=