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std::shared_ptr<T>:: owner_hash

From cppreference.net

Memory management library
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Allocators
Uninitialized memory algorithms
Constrained uninitialized memory algorithms
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Uninitialized storage (until C++20)
( until C++20* )
( until C++20* )
( until C++20* )

Garbage collector support (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
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 .

Contents

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::shared_ptr as keys in unordered associative containers

Example

See also

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