[pair.astuple]

🔗

template<class T1, class T2>
  struct tuple_size<pair<T1, T2>> : integral_constant<size_t, 2> { };

🔗

template<size_t I, class T1, class T2>
  struct tuple_element<I, pair<T1, T2>> {
    using type = see below ;
  };

Result: The type T1 if I is 0, otherwise the type T2.

🔗

template<size_t I, class T1, class T2>
  constexpr tuple_element_t<I, pair<T1, T2>>& get(pair<T1, T2>& p) noexcept;
template<size_t I, class T1, class T2>
  constexpr const tuple_element_t<I, pair<T1, T2>>& get(const pair<T1, T2>& p) noexcept;
template<size_t I, class T1, class T2>
  constexpr tuple_element_t<I, pair<T1, T2>>& get(pair<T1, T2>& p) noexcept;
template<size_t I, class T1, class T2>
  constexpr const tuple_element_t<I, pair<T1, T2>>& get(const pair<T1, T2>& p) noexcept;

Returns:

(4.1)
If I is 0, returns a reference to p.first.
(4.2)
If I is 1, returns a reference to p.second.

🔗

template<class T1, class T2>
  constexpr T1& get(pair<T1, T2>& p) noexcept;
template<class T1, class T2>
  constexpr const T1& get(const pair<T1, T2>& p) noexcept;
template<class T1, class T2>
  constexpr T1&& get(pair<T1, T2>& p) noexcept;
template<class T1, class T2>
  constexpr const T1&& get(const pair<T1, T2>& p) noexcept;

Returns: A reference to p.first.

🔗

template<class T2, class T1>
  constexpr T2& get(pair<T1, T2>& p) noexcept;
template<class T2, class T1>
  constexpr const T2& get(const pair<T1, T2>& p) noexcept;
template<class T2, class T1>
  constexpr T2&& get(pair<T1, T2>& p) noexcept;
template<class T2, class T1>
  constexpr const T2&& get(const pair<T1, T2>& p) noexcept;

Returns: A reference to p.second.

22 General utilities library [utilities]

22.3 Pairs [pairs]

22.3.4 Tuple-like access to pair [pair.astuple]