//********************************************************
// The following code example is taken from the book
//  C++23 - The Complete Guide
//  by Nicolai M. Josuttis (www.josuttis.com)
//  https://www.cppstd23.com
//
// The code is licensed under a
//  Creative Commons Attribution 4.0 International License
//  https://creativecommons.org/licenses/by/4.0/
//********************************************************


#include <print>
#include <vector>
#include <ranges>
#include <mdspan>
#include "print3d.hpp"

int main()
{
  std::vector vec{std::from_range, std::views::iota(1, 81)};  // vector with 1 to 80

  // mdspan of 2 * 5 * 3 elements with column-major order layout:
  std::mdspan<int, std::dextents<std::size_t, 3>, std::layout_left> 
     mdsL{vec.data(), 2, 5, 3};
  print3D(mdsL);

  // define the mapping:
  std::layout_left::mapping mapL3D{std::extents{2, 5, 3}};
  std::println("required_span_size(): {}", mapL3D.required_span_size());

  // and initialize an mdspan with it:
  std::mdspan mds2{vec.data(), mapL3D}; 
  static_assert(std::same_as<decltype(mdsL), decltype(mds2)>);    
  std::println("size:                 {}", mdsL.size());
  std::println("same mapping:         {}", mdsL.mapping() == mapL3D);
}