我想知道Ctypeid和typeofC 之间有什么区别。这是我所知道的：

• typeid在 C++ 头文件typeinfo中定义的type_info的文档中提到 。

• typeof在 C 的 GCC 扩展和 C++ Boost库中定义。

另外，这里是我创建的测试代码测试，我发现它typeid没有返回我的预期。为什么？

主文件

#include <iostream>  
#include <typeinfo>  //for 'typeid' to work

class Person {  
    public:
    // ... Person members ...  
    virtual ~Person() {}  
};

class Employee : public Person {  
    // ... Employee members ...  
};

int main () {  
    Person person;  
    Employee employee;  
    Person *ptr = &employee;  
    int t = 3;

    std::cout << typeid(t).name() << std::endl;  
    std::cout << typeid(person).name() << std::endl;   // Person (statically known at compile-time)  
    std::cout << typeid(employee).name() << std::endl; // Employee (statically known at compile-time)  
    std::cout << typeid(ptr).name() << std::endl;      // Person * (statically known at compile-time)  
    std::cout << typeid(*ptr).name() << std::endl;     // Employee (looked up dynamically at run-time  
                                                       // because it is the dereference of a pointer
                                                       // to a polymorphic class)  
 }

输出：

bash-3.2$ g++ -Wall main.cpp -o main  
bash-3.2$ ./main   
i  
6Person  
8Employee  
P6Person  
8Employee