jam::weak_root< T > Class Template Reference

An external weak slot, updated or cleared by collection without retaining its target.Keep it outside the managed heap. The heap must outlive even an expired attached root. Copies share a registration; moves leave the source detached and expired. Four-byte slot index; operations and destruction require the owning heap current. Operations require a quiescent collector. Old targets remain live during minor collection. More...

Inheritance diagram for jam::weak_root< T >:

Collaboration diagram for jam::weak_root< T >:

Public Member Functions
	weak_root () noexcept=default
	Construct a detached, expired weak root.
	weak_root (ptr< T > const &value) noexcept
	Register a pointer with the current heap, which must outlive this root.
	weak_root (root< T > const &value) noexcept
	Observe a strong root in the current heap without retaining its target.
template<class U> requires (!std::same_as<T, U>) && std::convertible_to<ptr<U>, ptr<T>>
	weak_root (ptr< U > const &value) noexcept
	Register a derived pointer through its base allocation-tracing hook.
bool	expired () const noexcept
	Whether this slot is null; does not initiate collection.
root< T >	lock () const noexcept
	Retain the current target, or return an empty root if expired. Requires the owning heap current; the strong root remains valid across collection.
void	reset () noexcept
	Unregister the slot and leave it detached and expired.
void	swap (weak_root &other) noexcept
	Exchange slots in the same heap without allocating or retaining either target.

Friends
void	swap (weak_root &a, weak_root &b) noexcept
	Exchange two external weak roots.

Detailed Description

template<class T>
class jam::weak_root< T >

An external weak slot, updated or cleared by collection without retaining its target.

Keep it outside the managed heap. The heap must outlive even an expired attached root. Copies share a registration; moves leave the source detached and expired. Four-byte slot index; operations and destruction require the owning heap current. Operations require a quiescent collector. Old targets remain live during minor collection.

Definition at line 2360 of file heap.ccm.

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

• heap.ccm