C++11 function可呼叫物件包裝器
阿新 • • 發佈：2018-12-26
// function.cpp : 此檔案包含 "main" 函式。程式執行將在此處開始並結束。 // #include "pch.h" #include <iostream> #include <functional> using namespace std; void func(void) { cout << __FUNCTION__ << endl; } class Foo { public: static int foo_func(int a) { cout << __FUNCTION__ << "(" << a << ") ->: "; return a; } }; class Bar { public: int operator()(int a) { cout << __FUNCTION__ << "(" << a << ") ->: "; return a; } }; class A { function<void()> callback_; public: A(const function<void()>& f):callback_(f){} void notify(void) { callback_(); } }; class FooA { public: void operator()(void) { cout << __FUNCTION__ << endl; } }; void call_when_even(int x, const function<void(int)>&f) { if (!(x&1)) { f(x); } } void output(int x) { cout << x << " "; } int main() { function<void(void)> fr1 = func; //bind a common function fr1(); // bind a static function function<int(int)> fr2 = Foo::foo_func; cout << fr2(123) << endl; // bind a functor Bar bar; fr2 = bar; cout << fr2(123) << endl; //1.function as callback FooA fooA; A aa(fooA); aa.notify(); //2. function as function parameters for (int i = 0;i<10;++i) { call_when_even(i, output); } cout << endl; }
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