xtensor xt::where索引相关函数的问题

template <class C, class S>
auto where(const xexpression<C>& condition, const S& shape)

#include <xtensor/xarray.hpp>
#include <xtensor/xio.hpp>
#include <xtensor/xview.hpp>
#include <xtensor/xindex_view.hpp>
#include <xtensor/xrandom.hpp>
#include <xtensor/xindex_iterator.hpp>
#include <iostream>

int main()
{
    // 创建一个随机的二维数组
    xt::xtensor<double, 2> a = xt::random::randn<double>({5, 5});

    std::cout << "Original array:\n" << a << std::endl;

    // 获取满足条件的元素索引
    auto indices = xt::where(a < 0.0);

    std::cout << "Indices of elements less than 0:\n";
    for (auto it = indices.begin(); it != indices.end(); ++it)
    {
        std::cout << "(" << it.index()[0] << ", " << it.index()[1] << ") ";
    }
    std::cout << std::endl;

    return 0;
}

Original array:
{{ 0.332474, -0.253746,  1.198918, -1.158154, -0.305833},
 { 1.3337  ,  0.729647,  0.20257 ,  1.501439, -0.755325},
 {-0.194777,  0.580024, -0.010596, -0.363994,  0.899585},
 { 0.175829, -0.869475,  0.711897,  0.078846, -0.486827},
 {-0.015584,  0.126642,  0.119617,  0.070372,  0.994727}}
 
Indices of elements less than 0:
(0, 1) (0, 3) (0, 4) (1, 4) (2, 0) (2, 3) (3, 1) (3, 4) (4, 0)