33 Concurrency support library [thread]

33.11 Safe reclamation [saferecl]

33.11.3 Hazard pointers [saferecl.hp] Class hazard_pointer [saferecl.hp.holder] General [saferecl.hp.holder.general]

namespace std { class hazard_pointer { public: hazard_pointer() noexcept; hazard_pointer(hazard_pointer&&) noexcept; hazard_pointer& operator=(hazard_pointer&&) noexcept; ~hazard_pointer(); [[nodiscard]] bool empty() const noexcept; template<class T> T* protect(const atomic<T*>& src) noexcept; template<class T> bool try_protect(T*& ptr, const atomic<T*>& src) noexcept; template<class T> void reset_protection(const T* ptr) noexcept; void reset_protection(nullptr_t = nullptr) noexcept; void swap(hazard_pointer&) noexcept; }; }
An object of type hazard_pointer is either empty or owns a hazard pointer.
Each hazard pointer is owned by exactly one object of type hazard_pointer.
[Note 1: 
An empty hazard_pointer object is different from a hazard_pointer object that owns an unassociated hazard pointer.
An empty hazard_pointer object does not own any hazard pointers.
— end note]