std::owner_hash
From cppreference.com
| Defined in header <memory>
|
||
| struct owner_hash; |
(since C++26) | |
This function object provides owner-based (as opposed to value-based) hashing of both std::weak_ptr and std::shared_ptr.
Nested types
| Nested type | Definition |
is_transparent
|
unspecified |
Member functions
| operator() |
calculates the hash of the shared-ownership pointer (function) |
std::owner_hash::operator()
| template< class T > std::size_t operator()( const std::shared_ptr<T>& key ) const noexcept; |
(1) | (since C++26) |
| template< class T > std::size_t operator()( const std::weak_ptr<T>& key ) const noexcept; |
(2) | (since C++26) |
Equivalent to return key.owner_hash();.
Parameters
| key | - | shared-ownership pointer to be hashed |
Return value
A hash value that is identical for any std::shared_ptr or std::weak_ptr object sharing the same ownership.
Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_smart_ptr_owner_equality |
202306L |
(C++26) | Enabling the use of std::shared_ptr and std::weak_ptr as keys in unordered associative containers
|
See also
| (C++26) |
provides owner-based hashing of shared pointers (public member function of std::shared_ptr<T>) |
| (C++26) |
provides owner-based hashing of weak pointers (public member function of std::weak_ptr<T>) |