# std::shared_ptr<T>::owner_hash

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< cpp‎ | memory‎ | shared 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::shared_ptr` as keys in unordered associative containers

### Example

| This section is incomplete Reason: example

### See also

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

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