std:: basic_common_reference < tuple-like >

Defined in header <tuple>
template < tuple - like TTuple, tuple - like UTuple, template < class > class TQual, template < class > class UQual > requires /* see below */ struct basic_common_reference < TTuple, UTuple, TQual, UQual > ;		(since C++23)

The common reference type of two tuple-like types is a std::tuple consists of the common reference types of all corresponding element type pairs of both types, where the cv and reference qualifiers on the tuple-like types are applied to their element types.

Given

• TTypes as the pack formed by the sequence of std:: tuple_element_t < i, TTuple > for every integer i in [ ​ 0 ​ , std:: tuple_size_v < TTuple > ) , and
• UTypes as the pack formed by the sequence of std:: tuple_element_t < i, UTuple > for every integer i in [ ​ 0 ​ , std:: tuple_size_v < UTuple > ) ,

the following constraints need to be satisfied:

• TTuple or UTuple is a std::tuple specialization.
• std:: is_same_v < TTuple, std:: decay_t < TTuple >> is true .
• std:: is_same_v < UTuple, std:: decay_t < UTuple >> is true .
• std:: tuple_size_v < TTuple > equals std:: tuple_size_v < UTuple > ( TTuple and UTuple have the same number of elements).
• std:: tuple < std:: common_reference_t < TQual < TTypes > ..., UQual < UTypes >> ... > denotes a type.

Member types

Member type	Definition
type	std:: tuple < std:: common_reference_t < TQual < TTypes > ..., UQual < UTypes >> ... >

Example

This section is incomplete Reason: no example

See also

common_reference basic_common_reference (C++20)	determines the common reference type of a group of types (class template)
std::basic_common_reference <std::pair> (C++23)	determines the common reference type of two pair s (class template specialization)