构造和操作2d数组的最佳现代c ++方法是什么 [英] what is the best modern c++ approach to construct and manipulate a 2d array

问题描述

就像标题中一样，我找到了很多解决方案.大多数人会说std::array<4, std::array<4, int>>或std::vector<std::vector<int>>是好的，但是，我发现它看起来很杂乱，很难扩展到多维数组.另外，我担心这些数组实际上是对象数组，可能会产生一些开销(我想是这样，并不是很确定).那么最好的方法是什么?

As in the title, I got to find tons of solutions doing this. Most people would say std::array<4, std::array<4, int>> or std::vector<std::vector<int>> are good, which, however, I find looks teidous and hard to extend to multi-dimensional arrays. Also, I fear that these arrays are actually object-arrays which is likely to be with some overhead (I guess so, not really certain). So what is the best way to do this ?

推荐答案

我碰巧发现了这个未经测试的示例.如果可行，那么很好，否则它是如何在1D数组上创建2D视图的一个示例:

I happen to have this completely untested example lying around. If it works, good, otherwise it is an example of how you might go about creating a 2D view onto a 1D array:

template<typename T>
class two_dee_array
{
public:
    two_dee_array(std::size_t row, std::size_t col)
        : v(row * col), stride(col) {}

    T& operator()(std::size_t row, std::size_t col)
        { return v[(row * stride) + col]; }

    T const& operator()(std::size_t row, std::size_t col) const
        { return v[(row * stride) + col]; }

    std::size_t col_size() const { return stride; }
    std::size_t row_size() const { return v.size() / stride; }

    auto begin() { return std::begin(v); }
    auto end() { return std::end(v); }

    auto begin() const { return std::begin(v); }
    auto end() const { return std::end(v); }

    auto cbegin() const { return std::cbegin(v); }
    auto cend() const { return std::cend(v); }

private:
    std::vector<T> v;
    std::size_t stride;
};

这篇关于构造和操作2d数组的最佳现代c ++方法是什么的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！