deduction guides for std::tuple

 

C++

Language

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Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Utilities library

Type support (basic types, RTTI, type traits)
Dynamic memory management
Error handling
Program utilities
Variadic functions
Library feature-test macros
Date and time
Function objects
initializer_list (C++11)
bitset
hash (C++11)
integer_sequence (C++14)
Relational operators (deprecated in C++20)
rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>=
Comparisons (C++20)
strong_order weak_order partial_order strong_equal weak_equal	strong_ordering weak_ordering partial_ordering strong_equality weak_equality	is_eqis_neqis_ltis_lteqis_gtis_gteq
common_comparison_category
Common vocabulary types
pair tuple (C++11) apply (C++17) make_from_tuple (C++17)	optional (C++17) any (C++17) variant (C++17)
Swap, forward and move
swap
exchange (C++14)
forward (C++11)
move (C++11)
move_if_noexcept (C++11)
Elementary string conversions
to_chars (C++17)
from_chars (C++17)
chars_format (C++17)
Type operations
declval (C++11)
as_const (C++17)
launder (C++17)

 

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>=

std::swap

get

Deduction guides(C++17)

Helper classes

tuple_size

tuple_element

uses_allocator

ignore

 

Defined in header <tuple>
template<class... UTypes> tuple(UTypes...) -> tuple<UTypes...>;	(1)	(since C++17)
template<class T1, class T2> tuple(std::pair<T1, T2>) -> tuple<T1, T2>;	(2)	(since C++17)
template<class Alloc, class... UTypes> tuple(std::allocator_arg_t, Alloc, UTypes...) -> tuple<UTypes...>;	(3)	(since C++17)
template<class Alloc, class T1, class T2> tuple(std::allocator_arg_t, Alloc, std::pair<T1, T2>) -> tuple<T1, T2>;	(4)	(since C++17)
template<class Alloc, class... UTypes> tuple(std::allocator_arg_t, Alloc, tuple<UTypes...>) -> tuple<UTypes...>;	(5)	(since C++17)

These deduction guides are provided for std::tuple to account for the edge cases missed by the implicit deduction guides, in particular, non-copyable arguments and array to pointer conversion.

Example

Run this code

#include <tuple>
int main()
{
    int a[2], b[3], c[4];
    std::tuple t1{a, b, c}; // explicit deduction guide is used in this case
}