c++ - 在其构造函数的成员初始化列表中使用对对象的引用

Question

是否可以在其构造函数的成员初始化列表中传递对对象（类型）的引用，以便按如下Container方式初始化成员：（ ideone上的代码）。Container

#include <cstdlib>
#include <iostream>

struct Container;

struct Member
{
    Member( Container& container ) : m_container( container )
    {
    }

    Container& m_container;
};

struct Container
{
    Container() : m_member( *this )
    {
    }

    Member m_member;
};

int main()
{
    Container c;
    return EXIT_SUCCESS;
}

代码可以编译，但我不确定它是否标准。

Answer 1

没关系; 成员引用被初始化为引用作为参数传递的对象。

但是，由于Container仍在构建中，因此您不能在该构造函数中访问它；对引用唯一能做的就是初始化另一个引用。

You must also make sure that you don't use that reference after the container is destroyed. In this example, it's fine - m_member, and the reference it contains, are destroyed along with the container.

Answer 2

That's ok, but do note that container in Member's constructor is not completely constructed yet, so you can't do anything with it except store that reference.