Registry is a container for all our entities and components. Components are stored in continuously in memory allowing for very fast iterations, a so called SoA approach. A set of unique components form an archetype, where every entity is mapped to an archetype. More...

#include <registry.hpp>

Inheritance diagram for co_ecs::registry:

Public Member Functions
template<component... Components>
constexpr auto	create (Components &&... args) -> entity_ref
	Creates a new entity and attaches the specified components to it.

constexpr auto	get_entity (entity ent) noexcept -> entity_ref
	Retrieves a mutable reference to an entity.

constexpr auto	get_entity (entity ent) const noexcept -> const_entity_ref
	Retrieves a constant reference to an entity.

constexpr auto	get_entity_const (entity ent) const noexcept -> const_entity_ref
	Retrieves a constant reference to an entity (alias).

template<component_reference... Args>
constexpr auto	view () -> co_ecs::view< Args... > requires(!const_component_references_v< Args... >)
	Create a non-const view based on component query in parameter pack.

template<component_reference... Args> requires const_component_references_v<Args...>
constexpr auto	view () const -> co_ecs::view< Args... >
	Create a const view based on component query in parameter pack.

template<component_reference... Args>
constexpr auto	single () -> std::optional< std::tuple< Args... > > requires(!const_component_references_v< Args... >)
	Returns a single tuple of components matching Args, if available in the view.

template<component_reference... Args> requires const_component_references_v<Args...>
constexpr auto	single () const -> std::optional< std::tuple< Args... > >
	Returns a single tuple of components matching Args, if available in the view.

template<typename F > requires (!detail::func_decomposer<F>::is_const)
constexpr void	each (F &&func)
	Executes a given function on each entity that matches the specified component requirements.

template<typename F > requires (detail::func_decomposer<F>::is_const)
constexpr void	each (F &&func) const
	Executes a given function on each entity that matches the specified component requirements, without modifying the entities.

constexpr std::size_t	size () const noexcept
	Returns the number of enitites in the registry.

constexpr bool	empty () const noexcept
	Checks if the registry currently manages any entities.

Public Member Functions inherited from co_ecs::base_registry
constexpr auto	alive (entity ent) const noexcept -> bool
	Checks if the specified entity is currently active within the registry.

void	destroy (entity ent)
	Destroys the given entity.

constexpr auto	archetypes () noexcept -> class archetypes &
	Provides access to the modifiable list of archetypes in the registry.

constexpr auto	archetypes () const noexcept -> const class archetypes &
	Provides access to the immutable list of archetypes in the registry.

constexpr auto	reserve () -> placeholder_entity
	Reserves an entity in a thread-safe manner.

constexpr void	sync ()
	Synchronizes concurently reserved entities.

template<component... C>
constexpr auto	has (entity ent) const -> bool
	Checks if the specified entity has all the given components.

constexpr void	visit (entity ent, auto &&func)
	Visit all components of an entity.

constexpr void	visit (entity ent, auto &&func) const
	Visit all components of an entity (const variant).

Additional Inherited Members
Protected Member Functions inherited from co_ecs::base_registry
template<component... Components>
constexpr auto	create_impl (Components &&... args) -> entity

template<component C>
constexpr auto	set_impl (entity ent) -> std::pair< bool, C * >

template<component C>
constexpr void	remove (entity ent)

constexpr auto	allocate () -> entity

entity	move (entity ent, base_registry &dest)

entity	copy (entity ent, base_registry &dest) const

entity	move (entity ent, base_registry &dest, placeholder_entity placeholder)

entity	copy (entity ent, base_registry &dest, placeholder_entity placeholder) const

entity	clone (entity ent)

entity	clone (entity ent, placeholder_entity placeholder)

Static Protected Member Functions inherited from co_ecs::base_registry
template<component... Args>
static constexpr auto	get_impl (auto &&self, entity ent) -> decltype(auto)

Protected Attributes inherited from co_ecs::base_registry
entity_pool	_entity_pool

class archetypes	_archetypes

detail::sparse_map< typename entity::id_t, entity_location >	_entity_archetype_map

Detailed Description

Registry is a container for all our entities and components. Components are stored in continuously in memory allowing for very fast iterations, a so called SoA approach. A set of unique components form an archetype, where every entity is mapped to an archetype.

Member Function Documentation

◆ create()

template<component... Components>

constexpr auto co_ecs::registry::create ( Components &&... args ) -> entity_ref

inlineconstexpr

Creates a new entity and attaches the specified components to it.

This method instantiates a new entity and assigns it the components provided as template arguments. It ensures all component types are unique, sets the components to the entity, and returns a reference to the newly created entity.

Example usage:

struct position {
    int x;
    int y;
};
 
int main() {
    ecs::registry registry;
    auto entity = registry.create<position>({1, 2});
    return 0;
}

Template Parameters

Component Component types to attach to the new entity.

Parameters

args	Instances of components to attach.

Returns: entity_ref A reference to the newly created entity, allowing further operations.

◆ each() [1/2]

template<typename F >
requires (!detail::func_decomposer<F>::is_const)

constexpr void co_ecs::registry::each ( F && func )

inlineconstexpr

Executes a given function on each entity that matches the specified component requirements.

This method iterates over each entity that has the required components and applies the function func.

Template Parameters

F	The type of the callable function to run on the entity components.

Parameters

func	A callable to run on entity components.

Example

struct position { double x, y; };
struct velocity { double vx, vy; };
 
void update_position(position& p, const velocity& v) {
    p.x += v.vx;
    p.y += v.vy;
}
 
ecs::registry registry;
registry.each(update_position);

◆ each() [2/2]

template<typename F >
requires (detail::func_decomposer<F>::is_const)

constexpr void co_ecs::registry::each ( F && func ) const

inlineconstexpr

Executes a given function on each entity that matches the specified component requirements, without modifying the entities.

This constant version of each allows for iteration over entities in a read-only fashion. It is suitable for operations that only need to read component data without modifying it, ensuring that the entity data remains unchanged. This method shares the same optimization benefits as its non-constant counterpart.

Template Parameters

F	The type of the callable function to run on the entity components.

Parameters

func	A callable to run on entity components, must not modify the entities.

◆ empty()

constexpr bool co_ecs::registry::empty ( ) const

inlineconstexprnoexcept

Checks if the registry currently manages any entities.

Returns: bool Returns true if the registry has no entities, false otherwise.

◆ get_entity() [1/2]

constexpr auto co_ecs::registry::get_entity ( entity ent ) const -> const_entity_ref

inlineconstexprnoexcept

Retrieves a constant reference to an entity.

This method returns a constant reference to the specified entity from the registry.

Parameters

ent	The entity to retrieve.

Returns: A constant reference to the specified entity.

Note: This method is marked as [[nodiscard]] and constexpr.

◆ get_entity() [2/2]

constexpr auto co_ecs::registry::get_entity ( entity ent ) -> entity_ref

inlineconstexprnoexcept

Retrieves a mutable reference to an entity.

This method returns a mutable reference to the specified entity from the registry.

Parameters

ent	The entity to retrieve.

Returns: A mutable reference to the specified entity.

Note: This method is marked as [[nodiscard]] and constexpr.

◆ get_entity_const()

constexpr auto co_ecs::registry::get_entity_const ( entity ent ) const -> const_entity_ref

inlineconstexprnoexcept

Retrieves a constant reference to an entity (alias).

This method is an alias for get_entity to return a constant reference to the specified entity from the registry.

Parameters

ent	The entity to retrieve.

Returns: A constant reference to the specified entity.

Note: This method is marked as [[nodiscard]] and constexpr.

◆ single() [1/2]

template<component_reference... Args>

constexpr auto co_ecs::registry::single ( ) -> std::optional<std::tuple<Args...>> requires(!const_component_references_v<Args...>)

inlineconstexpr

Returns a single tuple of components matching Args, if available in the view.

Returns: Optional tuple of components if found, otherwise empty optional

◆ single() [2/2]

template<component_reference... Args>
requires const_component_references_v<Args...>

constexpr auto co_ecs::registry::single ( ) const -> std::optional<std::tuple<Args...>>

inlineconstexpr

Returns a single tuple of components matching Args, if available in the view.

This method is available in const registry and allows accessing a single tuple of components matching Args. It returns an optional tuple, which is empty if no entities in the view match the component requirements.

Returns: Optional tuple of components if found, otherwise empty optional

◆ size()

constexpr std::size_t co_ecs::registry::size ( ) const

inlineconstexprnoexcept

Returns the number of enitites in the registry.

Returns: Number of entities present in the registry

◆ view() [1/2]

template<component_reference... Args>

constexpr auto co_ecs::registry::view ( ) -> co_ecs::view<Args...> requires(!const_component_references_v<Args...>)

inlineconstexpr

Create a non-const view based on component query in parameter pack.

Template Parameters

Args	Component references

Returns: view<Args...> A view

◆ view() [2/2]

template<component_reference... Args>
requires const_component_references_v<Args...>

constexpr auto co_ecs::registry::view ( ) const -> co_ecs::view<Args...>

inlineconstexpr

Create a const view based on component query in parameter pack.

Template Parameters

Args	Component references

Returns: view<Args...> A view

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

include/co_ecs/registry.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ create()

◆ each() [1/2]

Example

◆ each() [2/2]

◆ empty()

◆ get_entity() [1/2]

◆ get_entity() [2/2]

◆ get_entity_const()

◆ single() [1/2]

◆ single() [2/2]

◆ size()

◆ view() [1/2]

◆ view() [2/2]