std::get(std::tuple) - cppreference.com

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# std::get(std::tuple)

From cppreference.com
< cpp‎ | utility‎ | tuple

template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type& get( tuple<Types...>& t ); | (1) | (since C++11) (until C++14)
template< std::size_t I, class... Types > constexpr typename std::tuple_element<I, tuple<Types...> >::type& get( tuple<Types...>& t ); | (1) | (since C++14)
template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type&& get( tuple<Types...>&& t ); | (2) | (since C++11) (until C++14)
template< std::size_t I, class... Types > constexpr typename std::tuple_element<I, tuple<Types...> >::type&& get( tuple<Types...>&& t ); | (2) | (since C++14)
template< std::size_t I, class... Types > typename std::tuple_element<I, tuple<Types...> >::type const& get( const tuple<Types...>& t ); | (3) | (since C++11) (until C++14)
template< std::size_t I, class... Types > constexpr typename std::tuple_element<I, tuple<Types...> >::type const& get( const tuple<Types...>& t ); | (3) | (since C++14)
template< class T, class... Types > constexpr T& get(tuple<Types...>& t); | (4) | (since C++14)
template< class T, class... Types > constexpr T&& get(tuple<Types...>&& t); | (5) | (since C++14)
template< class T, class... Types > constexpr const T& get(const tuple<Types...>& t); | (6) | (since C++14)

1-3) Extracts the `Ith` element from the tuple. `I` is an integer value in `[0, sizeof...(Types))`.
4-6) 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.

### [edit] Parameters

t | - | tuple whose contents to extract

### [edit] Return value

1,4) Reference to the selected element of `t`.
2,5) Rvalue reference to the selected element of `t`, unless the element is of lvalue reference type, in which case lvalue reference is returned.
3,6) Const reference to the selected element of `t`.

### [edit] Exceptions

`noexcept` specification:
noexcept

### [edit] Example

Run this code

    #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)

### [edit] See also

std::get(std::array) | accesses an element of an `array` (function template) [edit]
std::get(std::pair) (C++11) | accesses an element of a `pair` (function template) [edit]

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Category:

- unconditionally noexcept