C++ 继承 - 无法访问的基础?

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时间:2020-08-28 16:45:07  来源:igfitidea点击:

C++ inheritance - inaccessible base?

c++inheritance

提问by bandai

I seem to be unable to use a base class as a function parameter, have I messed up my inheritance?

我似乎无法使用基类作为函数参数,我是否搞砸了我的继承?

I have the following in my main:

我的主要内容如下:

int some_ftn(Foo *f) { /* some code */ };
Bar b;
some_ftn(&b);

And the class Bar inheriting from Foo in such a way:

类 Bar 以这种方式从 Foo 继承:

class Bar : Foo
{
public:
    Bar();
    //snip

private:
    //snip
};

Should this not work? I don't seem to be able to make that call in my main function

这不应该工作吗?我似乎无法在我的主函数中进行调用

回答by Andrew Noyes

You have to do this:

你必须这样做:

class Bar : public Foo
{
    // ...
}

The default inheritance type of a classin C++ is private, so any publicand protectedmembers from the base class are limited to private. structinheritance on the other hand is publicby default.

classC++中 a 的默认继承类型是private,因此基类中的任何publicprotected成员都限于privatestruct另一方面,继承是public默认的。

回答by Jim Buck

By default, inheritance is private. You have to explicitly use public:

默认情况下,继承是私有的。您必须明确使用public

class Bar : public Foo

class Bar : public Foo