(1) | ||
template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type& get( tuple<Types...>& t ); | (since C++11) (until C++14) | |
template< std::size_t I, class... Types > constexpr std::tuple_element_t<I, tuple<Types...> >& get( tuple<Types...>& t ); | (since C++14) | |
(2) | ||
template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type&& get( tuple<Types...>&& t ); | (since C++11) (until C++14) | |
template< std::size_t I, class... Types > constexpr std::tuple_element_t<I, tuple<Types...> >&& get( tuple<Types...>&& t ); | (since C++14) | |
(3) | ||
template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type const& get( const tuple<Types...>& t ); | (since C++11) (until C++14) | |
template< std::size_t I, class... Types > constexpr std::tuple_element_t<I, tuple<Types...> >const& get( const tuple<Types...>& t ); | (since C++14) | |
template< std::size_t I, class... Types > constexpr std::tuple_element_t<I, tuple<Types...> >const&& get( const tuple<Types...>&& t ); | (4) | (since C++17) |
template< class T, class... Types > constexpr T& get(tuple<Types...>& t); | (5) | (since C++14) |
template< class T, class... Types > constexpr T&& get(tuple<Types...>&& t); | (6) | (since C++14) |
template< class T, class... Types > constexpr const T& get(const tuple<Types...>& t); | (7) | (since C++14) |
template< class T, class... Types > constexpr const T&& get(const tuple<Types...>&& t); | (8) | (since C++17) |
1-4) Extracts the
Ith
element from the tuple. I
is an integer value in [0, sizeof...(Types))
. 5-8) Extracts the element of the tuple
t
whose type is T
. Fails to compile if the tuple has more than one element of that type.Parameters
t | - | tuple whose contents to extract |
Return value
A reference to the selected element of t
.
Exceptions
noexcept
specification: noexcept
Example
#include <iostream> #include <string> #include <tuple> int main() { auto t = std::make_tuple(1, "Foo", 3.14); // index-based access std::cout << "(" << std::get<0>(t) << ", " << std::get<1>(t) << ", " << std::get<2>(t) << ")\n"; // type-based access std::cout << "(" << std::get<int>(t) << ", " << std::get<const char*>(t) << ", " << std::get<double>(t) << ")\n"; }
Output:
(1, Foo, 3.14) (1, Foo, 3.14)
See also
accesses an element of an array (function template) | |
(C++11) | accesses an element of a pair (function template) |
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