20 General utilities library [utilities]

20.4 Pairs [pairs]

20.4.4 Tuple-like access to pair [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 ; };
Mandates: .
Type: 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;
Mandates: .
Returns:
  • If I is 0, returns a reference to p.first.
  • 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;
Mandates: T1 and T2 are distinct types.
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;
Mandates: T1 and T2 are distinct types.
Returns: A reference to p.second.