WeakEntityManager< EntityType_, EntityIdType_ > Class Template Reference

Thread-safe registry that associates callback identifiers with entities without owning them. More...

#include <EntityManager.hpp>

Public Types
using	EntityType = EntityType_
	The registered entity type.
using	EntityIdType = EntityIdType_
	The type whose identifier domain is used by the registry.

Public Member Functions
	WeakEntityManager ()=default
	Constructs an empty weak entity registry.
Id< EntityIdType >	registerEntity (const std::shared_ptr< EntityType > &entity)
	Registers an entity and returns its callback identifier.
std::size_t	getLastId ()
bool	unregisterEntity (const std::shared_ptr< EntityType > &entity)
	Unregisters an entity.
bool	unregisterEntity (Id< EntityIdType > id)
	Unregisters an entity by identifier.
template<typename H>
bool	unregisterEntity (H *handle)
	Unregisters an entity using an opaque callback handle.
template<typename H>
bool	unregisterEntity (const H *handle)
	Unregisters an entity using a constant opaque callback handle.
std::shared_ptr< EntityType >	getEntity (Id< EntityIdType > id)
	Locks and returns the entity registered for an identifier.
template<typename H>
std::shared_ptr< EntityType >	getEntity (H *handle)
	Locks and returns the entity identified by an opaque callback handle.
template<typename H>
std::shared_ptr< EntityType >	getEntity (const H *handle)
	Locks and returns the entity identified by a constant opaque callback handle.
bool	contains (Id< EntityIdType > id)
std::optional< Id< EntityIdType > >	getId (const std::shared_ptr< EntityType > &entity)
bool	contains (const std::shared_ptr< EntityType > &entity)

Detailed Description

template<typename EntityType_, typename EntityIdType_ = EntityType_>
class WeakEntityManager< EntityType_, EntityIdType_ >

Thread-safe registry that associates callback identifiers with entities without owning them.

A callback obtains a temporary shared pointer with getEntity(), so an entity cannot be destroyed while that callback is using it. Unlike EntityManager, this registry does not keep an otherwise unused entity alive. Expired entries are removed lazily during lookups and explicitly by entity destructors.

Template Parameters

EntityType_	The registered entity type.
EntityIdType_	The type used to distinguish the identifier domain.

Member Function Documentation

contains() [1/2]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

bool WeakEntityManager< EntityType_, EntityIdType_ >::contains ( const std::shared_ptr< EntityType > & entity )

inline

Returns

true if the entity is currently registered and alive.

contains() [2/2]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

bool WeakEntityManager< EntityType_, EntityIdType_ >::contains ( Id< EntityIdType > id )

inline

Returns

true if the identifier currently refers to a live entity.

getEntity() [1/3]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

template<typename H>

std::shared_ptr< EntityType > WeakEntityManager< EntityType_, EntityIdType_ >::getEntity ( const H * handle )

inline

Locks and returns the entity identified by a constant opaque callback handle.

Template Parameters

H	The callback handle type.

Parameters

handle

The handle containing the registration identifier.

Returns

The registered entity, or an empty pointer if it has expired or is not registered.

getEntity() [2/3]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

template<typename H>

std::shared_ptr< EntityType > WeakEntityManager< EntityType_, EntityIdType_ >::getEntity ( H * handle )

inline

Locks and returns the entity identified by an opaque callback handle.

Template Parameters

H	The callback handle type.

Parameters

handle

The handle containing the registration identifier.

Returns

The registered entity, or an empty pointer if it has expired or is not registered.

getEntity() [3/3]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

std::shared_ptr< EntityType > WeakEntityManager< EntityType_, EntityIdType_ >::getEntity ( Id< EntityIdType > id )

inline

Locks and returns the entity registered for an identifier.

The returned shared pointer keeps the entity alive until the caller finishes using it.

Parameters

id	The registration identifier.

Returns

The registered entity, or an empty pointer if it has expired or is not registered.

getId()

template<typename EntityType_, typename EntityIdType_ = EntityType_>

std::optional< Id< EntityIdType > > WeakEntityManager< EntityType_, EntityIdType_ >::getId ( const std::shared_ptr< EntityType > & entity )

inline

Returns

The identifier of a live registered entity, if present.

getLastId()

template<typename EntityType_, typename EntityIdType_ = EntityType_>

std::size_t WeakEntityManager< EntityType_, EntityIdType_ >::getLastId ( )

inline

Returns

The numeric value of the most recently assigned identifier.

registerEntity()

template<typename EntityType_, typename EntityIdType_ = EntityType_>

Id< EntityIdType > WeakEntityManager< EntityType_, EntityIdType_ >::registerEntity ( const std::shared_ptr< EntityType > & entity )

inline

Registers an entity and returns its callback identifier.

Registering the same live entity more than once returns its existing identifier.

Parameters

entity

The entity to register.

Returns

The identifier associated with the entity.

unregisterEntity() [1/4]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

template<typename H>

bool WeakEntityManager< EntityType_, EntityIdType_ >::unregisterEntity ( const H * handle )

inline

Unregisters an entity using a constant opaque callback handle.

Template Parameters

H	The callback handle type.

Parameters

handle

The handle containing the registration identifier.

Returns

true if a registration was removed.

unregisterEntity() [2/4]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

bool WeakEntityManager< EntityType_, EntityIdType_ >::unregisterEntity ( const std::shared_ptr< EntityType > & entity )

inline

Unregisters an entity.

Parameters

entity

The entity to unregister.

Returns

true if a registration was removed.

unregisterEntity() [3/4]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

template<typename H>

bool WeakEntityManager< EntityType_, EntityIdType_ >::unregisterEntity ( H * handle )

inline

Unregisters an entity using an opaque callback handle.

Template Parameters

H	The callback handle type.

Parameters

handle

The handle containing the registration identifier.

Returns

true if a registration was removed.

unregisterEntity() [4/4]

template<typename EntityType_, typename EntityIdType_ = EntityType_>

bool WeakEntityManager< EntityType_, EntityIdType_ >::unregisterEntity ( Id< EntityIdType > id )

inline

Unregisters an entity by identifier.

Parameters

id	The registration identifier.

Returns

true if a registration was removed.