std::weak_ptr<T>::owner_hash

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std::weak_ptr
std::size_t owner_hash( ) const noexcept ;
(since C++26)

Returns an unspecified value such that for any object other where owner_equal(other) is true, owner_hash() == other.owner_hash() is true

This hashing is used to make shared and weak pointers usable as keys in unordered associative containers, typically through std::owner_hash.

Return value

A 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::weak_ptr as keys in unordered associative containers

Example

This section is incomplete
Reason: example

See also

(C++26)
 provides owner-based hashing for shared and weak pointers
(class)
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