添加运算符<<到 std::vector [英] Add operator&lt;&lt; to std::vector

问题描述

我想将 operator<<< 添加到 std::vector.这是运算符

I want to add operator<< to std::vector<string>. This is the operator

std::vector<std::string>& operator<<(std::vector<std::string>& op, std::string str) {
    op.push_back(str);
    return op;
}

现在我可以通过这种方式向 vector 添加元素:

Now I can add elements to vector this way:

std::vector<std::string> vec;
vec << "aaa" << "bbb" << "ccc";

但是下面的代码没有被编译，因为不能通过引用传递临时对象.

But the following code isn’t compiled since cant pass temporary object by reference.

std::vector<std::string>() << "AAA" << "BBB";

如何更改代码以将元素也添加到临时向量?

How can I change the code to add elements to temporary vectors too?

我有一个接受 const std::vector<std::string>& 参数的函数，所以我想在一行中将一个向量传递给它.

I have a function which accepts const std::vector<std::string>& argument so I want to pass to it a vector in one line.

推荐答案

你不能.可以实现的唯一方法是您的操作员是否是向量的成员.(出于某种原因，可以在临时对象上调用成员函数).

You can't. The only way it could be achieved would be if your operator was a member of the vector. (For some reason member functions can be invoked on temporaries).

作为一个非成员函数，虽然你所追求的是不可能的

As a nonmember function though what you're after is impossible

此外，重载 STL 类型(例如 std::vector)的运算符也不是一个好主意.我认为你想要完成的事情已经存在于 boost assign图书馆.我不相信你可以写得比他们更好，所以如果你需要这个，最好使用 boost.

Also it's not a very good idea to overload operators for STL types such as std::vector. I think what you're trying to accomplish is already present in boost assign library. I don't believe you can write it better than they have, so better use boost if you need this.

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