operator[]() [2/4]

template<typename... Ts>

template<concepts::identifier Id>
requires (concepts::uniquely_named<Ts...> && concepts::contains_field<Id, Ts...>)

decltype(auto) kumi::tuple< Ts >::operator[] ( Id const & ) &

inlineconstexprnoexcept

Extracts the element whose identifier matches Id from a kumi::tuple.

Note

Does not participate in overload resolution if there are no field which identifier matches Id in the tuple or if the tuple contains duplicate identifiers.

Template Parameters

Id	Identifier of the element to access

Returns

A reference to the selected element of current tuple.

Example:

#include <kumi/kumi.hpp>
#include <iostream>
 
int main()
{
  using namespace kumi::literals;
 
  kumi::tuple t = { "x"_id = 1, "y"_id = 2.3, "z"_id = 4.5f, "t"_id = '@' };
  std::cout << t << "\n";
  std::cout << t["x"_id] << "\n";
  std::cout << t["y"_id] << "\n";
  std::cout << t["z"_id] << "\n";
 
  t["t"_id]++;
 
  std::cout << t["t"_id] << "\n";
}