std::tuple_sizestd::pair - cppreference.com (original) (raw)
The partial specialization of std::tuple_size for pairs provides a compile-time way to obtain the number of elements in a pair, which is always 2, using tuple-like syntax.
[edit] Example
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2313 | C++11 | specializations for pair were not required to be derived from integral_constant | required |
[edit] See also
| Structured binding (C++17) | binds the specified names to sub-objects or tuple elements of the initializer[edit] |
|---|---|
| tuple_size(C++11) | obtains the number of elements of a tuple-like type (class template) [edit] |
| std::tuple_sizestd::array(C++11) | obtains the size of an array (class template specialization) [edit] |
| std::tuple_sizestd::tuple(C++11) | obtains the size ofa tuple (class template specialization) [edit] |
| std::tuple_sizestd::ranges::subrange(C++20) | obtains the size of a std::ranges::subrange (class template specialization) [edit] |
| std::tuple_elementstd::pair(C++11) | obtains the type of the elements of pair (class template specialization) [edit] |