to_record()

template<concepts::record_type Type>

auto to_record ( Type && r )

related

Converts a kumi::record_type to an instance kumi::record.

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

Parameters

r	kumi::product_type to convert

Returns

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

Example

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