to_tuple()

template<product_type Type>

constexpr auto kumi::to_tuple ( Type &&  t )

inlineconstexpr

Converts a kumi::product_type to an instance kumi::tuple.

Constructs an instance kumi::tuple from the elements of the kumi::product_type parameters

Parameters

t	kumi::product_type to convert

Returns

An instance of kumi::tuple constructed from each elements of t in order.

Example

 
#include <kumi/tuple.hpp>
#include <cstdint>
#include <iostream>
#include <type_traits>
#include <utility>
 
struct pixel
{
  int r, g, b;
};
 
template<std::size_t I>
decltype(auto) get(pixel const& p) noexcept
{
  if constexpr(I==0) return p.r;
  if constexpr(I==1) return p.g;
  if constexpr(I==2) return p.b;
}
 
template<std::size_t I>
decltype(auto) get(pixel& p) noexcept
{
  if constexpr(I==0) return p.r;
  if constexpr(I==1) return p.g;
  if constexpr(I==2) return p.b;
}
 
// Opt-in for Product Type semantic
template<>
struct kumi::is_product_type<pixel> : std::true_type
{};
 
// Adapt as structured bindable type
template<>
struct  std::tuple_size<pixel>
      : std::integral_constant<std::size_t,3> {};
 
template<std::size_t I> struct std::tuple_element<I,pixel> { using type = int; };
 
int main()
{
  pixel a = { 37, 15, 27 };
  auto b = kumi::to_tuple(a);
 
  std::cout << b << "\n";
}