get() [4/4]

template<str Name, product_type T>

decltype(auto) constexpr get ( T &&  t )

related

Extracts the values of the fields of a kumi::product_type.

Template Parameters

T	the type of the product_type from which to extract names.

Parameters

t	the product_type from which to extract names.

Returns

A tuple of references to the values of a kumi::product_type.

Example:

 
#include <kumi/kumi.hpp>
#include <iostream>
#include <string>
 
namespace ns
{
  struct people
  {
    std::string name;
    int         age;
  };
 
  template<std::size_t I>
  decltype(auto) get(people const& s) noexcept
  {
    if constexpr(I==0) return kumi::capture_field<"name">( s.name );
    if constexpr(I==1) return kumi::capture_field<"age" >( s.age  );
  }
 
  template<std::size_t I>
  decltype(auto) get(people& s) noexcept
  {
    if constexpr(I==0) return kumi::capture_field<"name">( s.name );
    if constexpr(I==1) return kumi::capture_field<"age" >( s.age  );
  }
}
 
// Opt-in for Record Type semantic
template<>
struct kumi::is_record_type<ns::people> : std::true_type
{};
 
// Adapt as structured bindable type
template<>
struct  std::tuple_size<ns::people>
      : std::integral_constant<std::size_t,2> {};
 
template<> struct std::tuple_element<0,ns::people> { using type = kumi::field_capture<"name",std::string>;  };
template<> struct std::tuple_element<1,ns::people> { using type = kumi::field_capture<"age" ,int        >;  };
 
int main()
{
  ns::people peter{"Peter Parker", 24};
    
  std::cout << kumi::get<"name">(peter) << "\n";
  std::cout << kumi::get<"age"> (peter) << "\n";
}