helios::ecs::EntityManager Class Reference

Entity manager responsible for entity creation, destruction, and validation. More...

#include <manager.hpp>

Public Member Functions
	EntityManager ()=default
	EntityManager (const EntityManager &other)
	EntityManager (EntityManager &&other) noexcept
	~EntityManager ()=default
EntityManager &	operator= (const EntityManager &other)
EntityManager &	operator= (EntityManager &&other) noexcept
void	Clear () noexcept
	Clears all entities.
void	Flush ()
	Creates reserved entities in the metadata.
template<typename F> requires std::invocable<F&, Entity>
void	Flush (const F &callback)
	Creates reserved entities and invokes callback for each flushed entity.
void	Reserve (size_t count)
	Reserves space for entities to minimize allocations.
Entity	ReserveEntity ()
	Reserves an entity ID that can be used immediately.
Entity	Create ()
	Creates a new entity.
template<typename OutputIt> requires std::output_iterator<OutputIt, Entity>
OutputIt	Create (size_t count, OutputIt &&out)
	Creates multiple entities at once and outputs them via an output iterator.
void	Destroy (Entity entity)
	Destroys an entity by incrementing its generation.
template<std::ranges::range R> requires std::same_as<std::ranges::range_value_t<R>, Entity>
void	Destroy (const R &entities)
	Destroys an entity by incrementing its generation.
bool	Validate (Entity entity) const noexcept
	Checks if an entity exists and is valid.
size_t	Count () const noexcept
	Gets the current number of living entities.
Entity::GenerationType	GetGeneration (Entity::IndexType index) const noexcept
	Returns current generation value for a given index (or kInvalidGeneration if out of range).

Detailed Description

Entity manager responsible for entity creation, destruction, and validation.

Manages entity lifecycle with generation counters to handle entity recycling safely.

Note

Partially thread-safe.

Definition at line 26 of file manager.hpp.

Constructor & Destructor Documentation

EntityManager() [1/3]

helios::ecs::EntityManager::EntityManager ( )

default

EntityManager() [2/3]

helios::ecs::EntityManager::EntityManager ( const EntityManager & other )

inline

Definition at line 187 of file manager.hpp.

EntityManager() [3/3]

helios::ecs::EntityManager::EntityManager ( EntityManager && other )

inlinenoexcept

Definition at line 194 of file manager.hpp.

~EntityManager()

helios::ecs::EntityManager::~EntityManager ( )

default

Member Function Documentation

Clear()

void helios::ecs::EntityManager::Clear ( )

inlinenoexcept

Clears all entities.

Destroys all entities and resets the manager state.

Note

Not thread-safe.

Definition at line 243 of file manager.hpp.

Count()

size_t helios::ecs::EntityManager::Count ( ) const

inlinenodiscardnoexcept

Gets the current number of living entities.

Returns count of entities that are currently alive.

Note

Thread-safe.

Returns

Number of living entities

Definition at line 159 of file manager.hpp.

Create() [1/2]

Entity helios::ecs::EntityManager::Create ( )

inlinenodiscard

Creates a new entity.

Reuses dead entity slots when available, otherwise creates new ones.

Note

Not thread-safe.

Returns

Newly created entity with valid index and generation

Definition at line 428 of file manager.hpp.

Create() [2/2]

template<typename OutputIt>
requires std::output_iterator<OutputIt, Entity>

OutputIt helios::ecs::EntityManager::Create ( size_t count, OutputIt && out )

inline

Creates multiple entities at once and outputs them via an output iterator.

Batch creation is more efficient than individual calls. Entities are written to the provided output iterator, avoiding internal allocations.

Note

Not thread-safe.

Template Parameters

OutputIt

Output iterator type that accepts Entity values

Parameters

count	Number of entities to create
out	Output iterator to write created entities to

Returns

Output iterator pointing past the last written entity

std::vector<Entity> entities;
entities.reserve(100);
manager.Create(100, std::back_inserter(entities));
 
// Or with pre-allocated array:
std::array<Entity, 10> arr;
manager.Create(10, arr.begin());
 
// Or with span output:
Entity buffer[50];
manager.Create(50, std::begin(buffer));

Definition at line 349 of file manager.hpp.

Destroy() [1/2]

template<std::ranges::range R>
requires std::same_as<std::ranges::range_value_t<R>, Entity>

void helios::ecs::EntityManager::Destroy ( const R & entities )

inline

Destroys an entity by incrementing its generation.

Marks entity as dead and adds its index to the free list for reuse. Entities that do not exist or are already destroyed are ignored.

Note

Not thread-safe.

Warning

Triggers assertion if any entity is invalid.

Template Parameters

R	Range type containing Entity elements

Parameters

entities

Entities to destroy

Definition at line 324 of file manager.hpp.

Destroy() [2/2]

void helios::ecs::EntityManager::Destroy ( Entity entity )

inline

Destroys an entity by incrementing its generation.

Marks entity as dead and adds its index to the free list for reuse. Entities that do not exist or are already destroyed are ignored.

Note

Not thread-safe.

Warning

Triggers assertion if entity is invalid.

Parameters

entity

Entity to destroy

Definition at line 307 of file manager.hpp.

Flush() [1/2]

void helios::ecs::EntityManager::Flush ( )

inline

Creates reserved entities in the metadata.

Processes all reserved entity IDs and creates their metadata.

Note

Not thread-safe.

Definition at line 48 of file manager.hpp.

Flush() [2/2]

template<typename F>
requires std::invocable<F&, Entity>

void helios::ecs::EntityManager::Flush ( const F & callback )

inline

Creates reserved entities and invokes callback for each flushed entity.

Processes all reserved entity IDs, initializes their metadata, and invokes callback exactly once per newly flushed entity.

Note

Not thread-safe.

Template Parameters

F	Callable type invocable with Entity

Parameters

callback

Callback invoked for each newly flushed entity

Definition at line 253 of file manager.hpp.

GetGeneration()

Entity::GenerationType helios::ecs::EntityManager::GetGeneration ( Entity::IndexType index ) const

inlinenodiscardnoexcept

Returns current generation value for a given index (or kInvalidGeneration if out of range).

Warning

Triggers assertion if index is invalid.

Definition at line 421 of file manager.hpp.

operator=() [1/2]

EntityManager & helios::ecs::EntityManager::operator= ( const EntityManager & other )

inline

Definition at line 205 of file manager.hpp.

operator=() [2/2]

EntityManager & helios::ecs::EntityManager::operator= ( EntityManager && other )

inlinenoexcept

Definition at line 222 of file manager.hpp.

Reserve()

void helios::ecs::EntityManager::Reserve ( size_t count )

inline

Reserves space for entities to minimize allocations.

Pre-allocates storage for the specified number of entities.

Note

Not thread-safe.

Parameters

count

Number of entities to reserve space for

Definition at line 287 of file manager.hpp.

ReserveEntity()

Entity helios::ecs::EntityManager::ReserveEntity ( )

inlinenodiscard

Reserves an entity ID that can be used immediately.

The actual entity creation is deferred until Flush() is called.

Note

Thread-safe.

Returns

Reserved entity with valid index and generation

Definition at line 294 of file manager.hpp.

Validate()

bool helios::ecs::EntityManager::Validate ( Entity entity ) const

inlinenodiscardnoexcept

Checks if an entity exists and is valid.

Validates both the entity structure and its current generation.

Note

Thread-safe for read operations.

Parameters

entity

Entity to validate

Returns

True if entity exists and is valid, false otherwise

Definition at line 410 of file manager.hpp.