虚函数的返回类型不同 [英] Differing return type for virtual functions

问题描述

虚拟函数的返回类型应该与基类或协变中的类型相同.但是为什么我们有这个限制?

A virtual function's return type should be the same type that is in base class, or covariant. But why do we have this restriction?

推荐答案

由于胡说八道:

struct foo
{
    virtual int get() const { return 0; }
};

struct bar : foo
{
    std::string get() const { return "this certainly isn't an int"; }
};

int main()
{
    bar b;
    foo* f = &b;

    int result = f->get(); // int, right? ...right?
}

让派生类返回完全不相关的内容是不明智的.

It isn't sensible to have a derived class return something completely unrelated.

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