front()

template<product_type Tuple>
requires ( size_v<Tuple> != 0)

KUMI_TRIVIAL_NODISCARD constexpr decltype(auto) kumi::front ( Tuple &&  t )

constexpr

Retrieves the front of a tuple.

Parameters

t	Base tuple

Returns

A reference to the first element of the tuple t

Helper type

namespace kumi::result
{
  template<product_type Tuple> struct front;
 
  template<product_type Tuple>
  using front_t = typename front<Tuple>::type;
}

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

Example

 
#include <kumi/tuple.hpp>
#include <iostream>
 
int main()
{
  kumi::tuple x{2.3,18, 5.f};
 
  std::cout << kumi::front(x) << "\n";
  std::cout << kumi::back(x)  << "\n";
 
  kumi::front(x) = 98.5;
  kumi::back(x)  = 66.f;
 
  std::cout << x << "\n";
}