【C++】别名

函数指针定义

方式

1. typedef

2. using

Examples

代码

#include <iostream>

int Sum(int x, int y)
{
    return x + y;
}

using FuncPtr_u = int (*)(int, int);    // warning: alias declarations are a C++11 extension [-Wc++11-extensions]
using FuncRef_u = int (&)(int, int);
using FuncTyp_u = int(int, int);

typedef int FuncTyp_t(int, int);
typedef int (*FuncPtr_t)(int, int);
typedef int (&FuncRef_t)(int, int);

int main()
{
    int result = 0;

    FuncPtr_u func_ptr = nullptr;
    func_ptr = Sum;
    result = func_ptr(1, 2);
    std::cout << "FuncPtr_u: " << result << std::endl;

    FuncPtr_t func_ptr1 = nullptr;
    func_ptr1 = Sum;
    result = func_ptr1(1, 2);
    std::cout << "FuncPtr_t: " << result << std::endl;

    FuncRef_u func_ref = Sum;
    // FuncRef_u func_ref;   // error: declaration of reference variable 'func_ref' requires an initializer
    // func_ref = Sum;
    result = func_ref(2, 3);
    std::cout << "FuncRef_u: " << result << std::endl;

    FuncRef_t func_ref1 = Sum;
    result = func_ref1(2, 3);
    std::cout << "FuncRef_t: " << result << std::endl;

    FuncTyp_u *func_typ = nullptr;
    func_typ = Sum;
    result = func_typ(3, 4);
    std::cout << "FuncTyp_u: " << result << std::endl;

    FuncTyp_t *func_typ1 = nullptr;
    func_typ1 = Sum;
    result = func_typ1(3, 4);
    std::cout << "FuncTyp_t: " << result << std::endl;

    return 0;
}
           

结果