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). | Member type | Definition |
|---|---|
type | std::tuple<std::common_reference_t<TQual<TTypes>..., UQual<UTypes>>...> |
|
(C++20) | determines the common reference type of a group of types (class template) |
|
(C++23) | determines the common reference type of two pairs (class template specialization) |
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