如何从向量初始化valarray？ [英] How do I initialize a valarray from a vector?

问题描述

它是确定/安全/良好的做法，写下列为了填充一个向量的
内容的valarray？

Is it ok/safe/good practice to write the following in order to fill a valarray with the content of a vector?

vector<int> myVect = {2,0,1,0,0,1,1,0,0,0}; // Any vector
valarray<int> myVala ( &(myVect[0]), myVect.size() );
//Edit: as suggested by Xeo, this code looks much cleaner (C++11)
valarray<int> myVala ( myVect.data(), myVect.size() );

它似乎工作正常，但我想确保它可以在任何情况下。

It seems to work fine but I would like to be sure it works on any case.

推荐答案

是的，这是完全正常的。向量的内容保证是连续的（见C ++标准中的 [vector.overview]，§1）。

Yes, this is perfectly fine. The contents of vector are guaranteed to be contiguous (see [vector.overview], §1 in C++ standard).

注意，由于C ++ 11，可以直接使用初始化器列表初始化 valarray 。

Note that since C++11, you can initialize valarray using initializer list directly.

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