如何初始化的std ::从C数组载体？ [英] How to initialize std::vector from C-style array?

问题描述

什么是初始化最廉价的方式的std ::矢量从C风格的数组？

What is the cheapest way to initialize a std::vector from a C-style array?

例如：在下面的类，我有一个矢量，但由于外界的限制，该数据将被传递作为C风格数组：

Example: In the following class, I have a vector, but due to outside restrictions, the data will be passed in as C-style array:

class Foo {
  std::vector<double> w_;
public:
  void set_data(double* w, int len){
   // how to cheaply initialize the std::vector?
}

很显然，我可以叫 w_.resize（），然后遍历所有的元素，或致电的std ::复制（）。是否有更好的方法？

Obviously, I can call w_.resize() and then loop over the elements, or call std::copy(). Are there any better methods?

推荐答案

不要忘了，你可以把指针作为迭代器：

Don't forget that you can treat pointers as iterators:

w_.assign(w, w + len);

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