std::get(std::pair)
Defined in header <utility>
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(1) | ||
template< size_t I, class T1, class T2 > typename std::tuple_element<I, std::pair<T1,T2> >::type& |
(1) | (since C++11) (until C++14) |
template< size_t I, class T1, class T2 > constexpr std::tuple_element_t<I, std::pair<T1,T2> >& |
(1) | (since C++14) |
(2) | ||
template< size_t I, class T1, class T2 > const typename std::tuple_element<I, std::pair<T1,T2> >::type& |
(2) | (since C++11) (until C++14) |
template< size_t I, class T1, class T2 > constexpr const std::tuple_element_t<I, std::pair<T1,T2> >& |
(2) | (since C++14) |
(3) | ||
template< size_t I, class T1, class T2 > typename std::tuple_element<I, std::pair<T1,T2> >::type&& |
(3) | (since C++11) (until C++14) |
template< size_t I, class T1, class T2 > constexpr std::tuple_element_t<I, std::pair<T1,T2> >&& |
(3) | (since C++14) |
template< size_t I, class T1, class T2 > constexpr const std::tuple_element_t<I, std::pair<T1,T2> >&& |
(4) | (since C++17) |
template <class T, class U> constexpr T& get(std::pair<T, U>& p) noexcept; |
(5) | (since C++14) |
template <class T, class U> constexpr const T& get(const std::pair<T, U>& p) noexcept; |
(6) | (since C++14) |
template <class T, class U> constexpr T&& get(std::pair<T, U>&& p) noexcept; |
(7) | (since C++14) |
template <class T, class U> constexpr const T&& get(const std::pair<T, U>&& p) noexcept; |
(8) | (since C++17) |
template <class T, class U> constexpr T& get(std::pair<U, T>& p) noexcept; |
(9) | (since C++14) |
template <class T, class U> constexpr const T& get(const std::pair<U, T>& p) noexcept; |
(10) | (since C++14) |
template <class T, class U> constexpr T&& get(std::pair<U, T>&& p) noexcept; |
(11) | (since C++14) |
template <class T, class U> constexpr const T&& get(const std::pair<U, T>&& p) noexcept; |
(12) | (since C++17) |
Extracts an element from the pair using tuple-like interface.
The index-based overloads (1-4) fail to compile if the index I
is neither 0 nor 1.
The type-based overloads (5-12) fail to compile if the types T
and U
are the same.
Parameters
p | - | pair whose contents to extract |
Return value
1-4) Returns a reference to
p.first
if I==0
and a reference to p.second
if I==1
.5-8) Returns a reference to
p.first
.9-12) Returns a reference to
p.second
.Example
Run this code
#include <iostream> #include <utility> int main() { auto p = std::make_pair(1, 3.14); std::cout << '(' << std::get<0>(p) << ", " << std::get<1>(p) << ")\n"; std::cout << '(' << std::get<int>(p) << ", " << std::get<double>(p) << ")\n"; }
Output:
(1, 3.14) (1, 3.14)
See also
tuple accesses specified element (function template) | |
accesses an element of an array (function template) | |
(C++17) |
reads the value of the variant given the index or the type (if the type is unique), throws on error (function template) |