STL算法取整个容器而不是.begin（），end（）作为arg？ [英] STL algorithms taking the whole container rather than .begin(), end() as arg?

问题描述

独立的STL算法（如 std :: count_if ）使用一对迭代器。在所有情况下，我使用那些（在所有的例子，我在网上看到！），我发现自己键入

Stand-alone STL algorithms (like std::count_if) take pair of iterators. In all cases where I use those (and in all examples I've seen online!), I find myself typing

std::count_if(myContainer.begin(),myContainer.end(), /* ... */ );

有什么原因为什么样式的速记模板

Is there a reason why shorthand templates of the style

std::count_if(myContainer, /* ... */ );

，因为更多的不是整个容器上执行的操作？我只是忽略它吗？对于c ++ 11和c ++ 03，答案是不同的吗？

are not provided, given that more of than not is the operaation performed on the whole container? Did I just overlook it? Is the answer different for c++11 and c++03?

推荐答案

有一个不错的 blog-post by Herb Sutter讨论这个问题。要点是，如果对于具有相同数量的模板参数的算法的过载已经存在，则为算法添加基于容器的重载可以产生歧义。概念旨在解决这个问题。

There is a nice blog-post by Herb Sutter discussing the question. The gist is that adding container-based overloads for algorithms can create ambiguities if an overload for that algorithm with the same number of template-parameters already exists. Concepts were intended to fix that problem.

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