为什么标准C ++容器适配器不提供清晰的功能？ [英] Why don't the standard C++ container adaptors provide a clear function?

问题描述

有没有人知道为什么std :: queue，std :: stack和std :: priority_queue不提供 clear（）成员函数？我必须伪造一个这样的：

Does anyone know why std::queue, std::stack, and std::priority_queue don't provide a clear() member function? I have to fake one like this:

std::queue<int> q;
// time passes...
q = std::queue<int>();  // equivalent to clear()

IIRC， clear c $ c>由可以充当底层容器的所有内容提供。有没有很好的理由没有容器适配器提供它？

IIRC, clear() is provided by everything that could serve as the underlying container. Is there a good reason to not have the container adaptors provide it?

推荐答案

嗯，我想这是因为 clear 不被认为是队列，priority_queue或堆栈上的有效操作（顺便说一句，deque不是，而是适配器，而是容器）。

Well, I think this is because clear was not considered a valid operation on a queue, a priority_queue or a stack (by the way, deque is not and adaptor but a container).

使用容器
适配器队列而不是容器
deque的唯一原因是，你是
只执行队列操作，
没有其他操作。 （来自队列上的sgi页面）

所以当使用队列时，你可以做的是push / pop元素;清除队列可以被视为违反FIFO概念。因此，如果你需要清除你的队列，也许它不是一个队列，你应该更好地使用deque。

So when using a queue, all you can do is push/pop elements; clearing the queue can be seen as a violation of the FIFO concept. Consequently, if you need to clear your queue, maybe it's not really a queue and you should better use a deque.

然而，这个概念有点狭窄，我认为你应该清除队列是公平的。

However, this conception of things is a little narrow-minded, and I think clearing the queue as you do is fair enough.

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