member_cast()

template<typename Target, concepts::product_type T>

auto kumi::member_cast ( T && t )

inlinenodiscardconstexpr

Converts a product_type<Ts...> to an instance of a product_type<Target...>.

Template Parameters

Target

destination type to associate to each member of the product type

Parameters

t	Product type to convert

Returns

A Product type containing the values of b where each member is of type Target

Helper type

namespace kumi::result
{
  template<typename Target, product_type T> struct member_cast;
 
  template<typename Target, Product_type T>
  using member_cast_t = typename member_cast<Target, T>::type;
}

Computes the return type of a call to kumi::member_cast

Examples:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  kumi::tuple a = { 14.f, 42, 55, short{89} };
  auto b = kumi::member_cast<char>(a);
 
  std::cout << a << "\n";
  std::cout << b << "\n";
}

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
  kumi::record a = { "a"_id = 14.f, "b"_id = 42,"c"_id =  55, "d"_id = short{89} };
  auto b = kumi::member_cast<char>(a);
 
  std::cout << a << "\n";
  std::cout << b << "\n";
}