Entities

Entities are ecs_entity_t handles created by a world.

C

ecs_entity_t entity = ecs_new();

C++

ecs::init();
auto entity = ecs::entity::create();

New entities start alive and have no user components.

For abstract entities, bases, and inherited components, see Inheritance.

Liveness

Use ecs_is_alive() with entity handles created by the same world:

C

if (ecs_is_alive(entity)) {
    /* entity can be used */
}

C++

if (entity.is_alive()) {
    // entity can be used
}

ecs_is_alive() is not a general validator for arbitrary integers. Passing ids that did not come from the world is not supported.

Destroy Entities

C

ecs_kill(entity);

C++

entity.kill();

Killing an entity removes all of its components, runs remove hooks, removes the entity from its current archetype table, and invalidates the handle.

After ecs_kill(), do not use the old handle with component access functions.

Handle Layout

The public API treats ecs_entity_t as an opaque handle. Internally, SIECS packs an entity index and generation into a 64-bit value so stale handles can be detected.