C++11:function&bind使用例

#include <functional>

  
#include <iostream>

  
 

  
struct Foo {

  
    Foo(int num) : num_(num) {}

  
    void print_add(int i) const { std::cout << num_+i << '
'; }

  
    int num_;

  
};

  
 

  
void print_num(int i)

  
{

  
    std::cout << i << '
';

  
}

  
 

  
struct PrintNum {

  
    void operator()(int i) const

  
    {

  
        std::cout << i << '
';

  
    }

  
};

  
 

  
int main()

  
{

  
    // store a free function

  
    std::function<void(int)> f_display = print_num;

  
    f_display(-9);

  
 

  
    // store a lambda

  
    std::function<void()> f_display_42 = []() { print_num(42); };

  
    f_display_42();

  
 

  
    // store the result of a call to std::bind

  
    std::function<void()> f_display_31337 = std::bind(print_num, 31337);

  
    f_display_31337();

  
 

  
    // store a call to a member function

  
    std::function<void(const Foo&, int)> f_add_display = &Foo::print_add;

  
    const Foo foo(314159);

  
    f_add_display(foo, 1);

  
 

  
    // store a call to a member function and object

  
    using std::placeholders::_1;

  
    std::function<void(int)> f_add_display2= std::bind( &Foo::print_add, foo, _1 );

  
    f_add_display2(2);

  
 

  
    // store a call to a function object

  
    std::function<void(int)> f_display_obj = PrintNum();

  
    f_display_obj(18);

  
}