从 C++ (STL) 中的(它的)迭代器类型获取容器类型

Obtain container type from (its) iterator type in C++ (STL)(从 C++ (STL) 中的(它的)迭代器类型获取容器类型)

问题描述

给定一个容器来获取相关的迭代器很容易，例如:

It is easy given a container to get the associated iterators, example:

std::vector<double>::iterator i; //An iterator to a std::vector<double>

我想知道是否有可能，给定一个迭代器类型，推导出对应容器"的类型(这里我假设每个容器只有一个(非常量)迭代器).

I was wondering if it is possible, given an iterator type, to deduce the type of the "corresponding container" (here I am assuming that for each container there is one and only one (non-const) iterator).

更准确地说，我想要一个适用于所有 STL 容器的模板元函数(无需为每个容器手动专门化它)，例如:

More precisely, I would like a template metafunction that works with all STL containers (without having to specialize it manually for each single container) such that, for example:

ContainerOf< std::vector<double>::iterator >::type 

评估为

std::vector<double>

有可能吗?如果没有，为什么?

Is it possible? If not, why?

在此先感谢您的帮助！

推荐答案

我认为这不可能.在某些 STL 库中，您实际上有一个向量迭代器作为指针类型，即std::vector<T>::iterator 是一个 T* 所以我想不出有什么方法可以让你从那里回到容器类型.

I don't think this would be possible. On some STL libraries you actually have a vector iterator as a pointer type, i.e. std::vector<T>::iterator is a T* so I can't think of any way you could get back to the container type from that.

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