member_cast

template<typename T>

member_cast_t<T> kumi::member_cast {}

inlineconstexprnodiscard

Callable object converting a product_type<Ts...> to an instance of a product_type<Target...>.

Header file

#include <kumi/algorithm/member_cast.hpp>

Call Signature

template<typename Target, product_type T>
constexpr auto member_cast<Target>(T && t) noexcept;

Template Parameters

• Target: destination type to associate to each member of the product type t

Parameters

• t: Product Type to convert

Return value

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

Helper type

    template<typename Target, kumi::concepts::product_type T> struct member_cast
    {
      using type = decltype(kumi::member_cast<Target>(std::declval<T>()));
    };
 
    template<typename Target, kumi::concepts::product_type T>
    using member_cast_t = typename kumi::result::member_cast<Target, T>::type;

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

Examples

Tuple

#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";
}

Record

#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";
}