std::function存储 voidPrintNum(inti){std::cout<<"store a function pointer: "<<i<<std::endl;}classA{public:A(intnum):num_(num){}voidPrintNum(intn)const{std::cout<<"store a call to a member function: "<<num_<<std::endl;}private:intnum_;};classB{public:B(intnum):num_(num)...
//std::function 可以存储任意 "CopyConstructible" 和 "Callable" 的对象,比如 : functions / lambda expressions / bind expressions / pointers to member functions / pointers to data members. //std::function 是通过拷贝构造的方式整体存储传给自己的对象的,因此即便那个对象在后面因为离开作用域或者主动销毁...
std::function<int(Foo const&)> f_num = &Foo::num_; std::cout << "num_: " << f_num(foo) << '\n'; // store a call to a member function and object using std::placeholders::_1; //参数绑定 std::function<void(int)> f_add_display2 = std::bind( &Foo::print_add, foo,...
std::function<int(int,int,int,int)> f; f = Caller; f(10,20,30,40); return0; } 内存结构如下: 由此我们可以发现 std::function 是利用一个 _Compressed_pair<_Alloc, _Callable> _Mypair; 拷贝了元素的数据信息。 主要的初始化过程为: emplate<class_Fx, class_Alloc> void_Reset_alloc(_Fx&&...
一、std::function 1、概念 std::function是一个函数包装器模板,最早来自boost库,对应其boost::function函数包装器。在c++11中,将boost::function纳入标准库中。该函数包装器模板能包装任何类型的可调用元素(callable element),例如普通函数和函数对象。包装器对象可以进行拷贝,并且包装器类型仅仅只依赖于其调用特征(ca...
C++中的高阶函数:以std::function优雅地实现回调 1. 简介 1.1 C++高阶函数的概念 在函数式编程语言中,高阶函数(Higher-order Function)是一个常见的概念,它通常被定义为满足下列条件之一的函数: 接受一个或多个函数作为输入(参数) 输出(返回值)是一个函数 ...
std::cout << "1) bind to a pointer to member function: "; Foo foo; // 这里的&foo就是为了补齐成员变量里面的默认参数this auto f3 = std::bind(&Foo::print_sum, &foo, 95, _1); f3(5); std::cout << "2) bind to a mem_fn that is a pointer to member function: "; } 执行...
Instances of std::function can store, copy, and invoke any CopyConstructible Callable target–functions, lambda expressions, bind expressions, or other function objects, as well as pointers to member functions and pointers to data members std::function 是一个函数包装器模板,一个 std::function 类...
seminar.cpp: In member function ‘std::vector<unsigned char> Tom::Car::Car::road(Nor::Driving&)’: seminar.cpp:22:71: error: ISO C++ forbids taking the address of an unqualified or parenthesized non-static member function to form a pointer to member function. Say ‘&Tom::Car::Car::...
Args> struct function_traits // we specialize for pointers to member function { enum { arity = sizeof...(Args) }; // arity is the number of arguments. typedef ReturnType result_type; typedef typename std::tuple_element<i, std::tuple<Args...>>::type type; }; template <class Func...