C++函数指针 各个方式表现 和 使用方法

#include <iostream>

using namespace std;


void test()
{
    cout << "test with no arguments
";
}
void test2(int a)
{
    cout << "test with one arguments "<< a <<"
";
}
void* test3()
{
    cout << "test with no argumetens and return"<<"
";
    int a =10;
    return (void*)&a;
}
void *test4(int b)
{
    cout <<"test with one arguments and return pointer"
    << "
";
    return (void*)&b;
}


extern int main01() {
    typedef void (*pf)();
    pf _func_01 = test;
    _func_01();

    typedef void (*pf_one)(int);
    pf_one _func_02 = test2;
    _func_02(2);

    typedef void *(*pf_sce)();
    pf_sce _func_03 = test3;
    cout << *((int *) _func_03()) << endl;

    typedef void *(*pf_sce_one)(int);
    pf_sce_one _func_04 = test4;
    cout << *((int *) _func_04(5)) << endl;
}