c++11:function的用法

#include <functional>
void print_num(int i)
{
    cout << "i" << endl;
}

function<void(int)> f_display = print_num;
f_display(-9);

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

function<void()> f_display_32337 = bind(print_num, 32337); //对bind不明白参考bind
f_display_32337();

#include <functional>
stuct Foo {
   Foo(int num) : num_(num) {}
   void print_add(int i) const { cout << num_ + i << endl;}
   int num_;          
};

function<void(const Foo&, int)> f_add_display = &Foo::print_add;
const Foo foo(314159);
f_add_display(foo, 1);

function<void(int)> f_add_display2 = bind(&Foo::print_add, foo, placeholders::_1);
f_add_display2(2);

  1 #include <functional>
  2 #include <iostream>
  3 
  4 using namespace std;
  5 
  6 class Scope {
  7 public:
  8     explicit Scope(function<void()> o) :
  9         on_exit_(o) {}
 10     ~Scope() { on_exit_(); }
 11 private:
 12     function<void()> on_exit_;
 13 };
 14 
 15 int main()
 16 {
 17     Scope scope([]() { cout << "close" << endl; });
 18 }