typedef void(*Fun)(void); 请问这个是怎么进行替换的 Fun pFun

[bai1124]

#include <iostream>
typedef void(*Fun)(void);
using namespace std;
class Base
{
public:
virtual void f()
{
cout << "Base::f" << endl;
}
virtual void g()
{
cout << "Base::g" << endl;
}
virtual void h()
{
cout << "Base::h" << endl;
}

};

int main()
{
Base b;
Fun pFun = NULL;
cout << "虚函数表地址：" << (int*)(&b) << endl;
cout << "虚函数表 — 第一个函数地址：" << (int*)*(int*)(&b) << endl;

// Invoke the first virtual function
pFun = (Fun)*((int*)*(int*)(&b));
pFun();
}
请问Fun pFun = NULL;这句话是怎么被typedef void(*Fun)(void);这个所替换的

[fly_dragon_fly]

typedef 产生定义，不是宏

[ysok]

typedef定义的是函数指针，这个指针可以指向一个函数

[赵4老师]

typedef typedef type-declaration synonym; The typedef keyword defines a synonym for the specified type-declaration. The identifier in the type-declaration becomes another name for the type, instead of naming an instance of the type. You cannot use the typedef specifier inside a function definition. A typedef declaration introduces a name that, within its scope, becomes a synonym for the type given by the decl-specifiers portion of the declaration. In contrast to the class, struct, union, and enum declarations, typedef declarations do not introduce new types — they introduce new names for existing types. Example // Example of the typedef keyword typedef unsigned long ulong; ulong ul; // Equivalent to "unsigned long ul;" typedef struct mystructtag { int i; float f; char c; } mystruct; mystruct ms; // Equivalent to "struct mystructtag ms;" typedef int (*funcptr)(); // funcptr is synonym for "pointer // to function returning int" funcptr table[10]; // Equivalent to "int (*table[10])();"

[只此冒泡君]

typedef定义了函数指针 你可以把Fun理解为 和 int 这样的关键字一样！

[booirror]

#define 才有替换之说。