jh::weak_ptr_hash< T > Struct Template Reference

Content-based hash functor for std::weak_ptr<T>. More...

#include <jh/concurrent/observe_pool.h>

Public Member Functions
std::size_t	operator() (const std::weak_ptr< T > &ptr) const noexcept

Detailed Description

template<typename T>
requires jh::concepts::extended_hashable<T>
struct jh::weak_ptr_hash< T >

Content-based hash functor for std::weak_ptr<T>.

Behavior

• If the pointer is expired, returns 0.
• If valid, locks and applies the unified jh::hash<T> functor to the underlying object.
• Ensures consistent results during concurrent insertion into a jh::observe_pool by performing a single well-defined hash access per locked instance.

Purpose

Enables jh::observe_pool and jh::conc::pointer_pool to hash weakly referenced shared objects by logical content, without altering ownership or extending object lifetimes.

Version Note (since 1.3.5)

Starting with 1.3.5, weak_ptr_hash<T> supports automatic hash deduction through jh::hash<T>, which transparently resolves hashing via the following precedence chain:

std::hash<T>{ }(v)
  >  hash(v)
  >  v.hash()

This allows any type declaring a valid hash mechanism — standard, ADL-based, or member-based — to participate in pooling without the need for custom specialization.

Template Parameters

T	The managed type, which must satisfy jh::concepts::extended_hashable.

See also

jh::concepts::extended_hashable

jh::hash

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The documentation for this struct was generated from the following file:

• include/jh/concurrent/observe_pool.h