std::make_tuple

 

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std::tuple

Member functions

tuple::tuple

tuple::operator=

tuple::swap

Non-member functions

make_tuple

tie

forward_as_tuple

tuple_cat

operator==operator!=operator<operator<=operator>operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)

swap(std::tuple)

get(std::tuple)

Helper concepts

tuple-like (C++23)

Helper classes

tuple_size<std::tuple>

tuple_element<std::tuple>

uses_allocator<std::tuple>

basic_common_reference<std::tuple> (C++23)

common_type<std::tuple> (C++23)

formatter<std::tuple> (C++23)

ignore

Deduction guides(C++17)

 

Defined in header <tuple>
template<class... Types> std::tuple<VTypes...> make_tuple( Types&&... args);		(since C++11) (constexpr since C++14)

Creates a tuple object, deducing the target type from the types of arguments.

For each Ti in Types..., the corresponding type Vi in VTypes... is std::decay<Ti>::type unless application of std::decay results in std::reference_wrapper<X> for some type X, in which case the deduced type is X&.

Parameters

args

-

zero or more arguments to construct the tuple from

Return value

A std::tuple object containing the given values, created as if by std::tuple<VTypes...>(std::forward<Types>(t)...).

Possible implementation

template<class T>struct unwrap_refwrapper {using type = T;};   template<class T>struct unwrap_refwrapper<std::reference_wrapper<T>>{using type = T&;};   template<class T>using unwrap_decay_t =typename unwrap_refwrapper<typenamestd::decay<T>::type>::type;// or use std::unwrap_ref_decay_t (since C++20)   template<class... Types>constexpr// since C++14std::tuple<unwrap_decay_t<Types>...> make_tuple(Types&&... args){returnstd::tuple<unwrap_decay_t<Types>...>(std::forward<Types>(args)...);}

Example

Run this code

#include <iostream>#include <tuple>#include <functional>   std::tuple<int, int> f()// this function returns multiple values{int x =5;return std::make_tuple(x, 7);// return {x,7}; in C++17}   int main(){// heterogeneous tuple constructionint n =1;auto t = std::make_tuple(10, "Test", 3.14, std::ref(n), n); n =7;std::cout<<"The value of t is ("<< std::get<0>(t)<<", "<< std::get<1>(t)<<", "<< std::get<2>(t)<<", "<< std::get<3>(t)<<", "<< std::get<4>(t)<<")\n";   // function returning multiple valuesint a, b;std::tie(a, b)= f();std::cout<< a <<' '<< b <<'\n';}

Output:

The value of t is (10, Test, 3.14, 7, 1) 5 7

See also

tie (C++11)	creates a tuple of lvalue references or unpacks a tuple into individual objects (function template)
forward_as_tuple (C++11)	creates a tuple of forwarding references (function template)
tuple_cat (C++11)	creates a tuple by concatenating any number of tuples (function template)
apply (C++17)	calls a function with a tuple of arguments (function template)