co_ecs::view< Args > Class Template Reference

A view lets you get a range over components of Args out of a registry. More...

#include <view.hpp>

Public Member Functions
	view (registry_type registry) noexcept
	Constructs a new view object.
auto	single () -> std::optional< std::tuple< Args... > > requires(!is_const)
	Returns a single tuple of components matching Args, if available in the view.
auto	single () const -> std::optional< std::tuple< Args... > > requires(is_const)
	Returns a single tuple of components matching Args, if available in the view (const version).
auto	each () -> decltype(auto) requires(!is_const)
	Returns an iterator that yields a std::tuple<Args...>.
auto	each () const -> decltype(auto) requires(is_const)
	Returns an iterator that yields a std::tuple<Args...> (const version).
void	each (auto &&func)
	Runs a function on every entity that matches the Args requirement.
void	each (auto &&func) const
	Runs a function on every entity that matches the Args requirement (const version).
void	par_each (auto &&func)
	Runs a function on every entity that matches the Args requirement in parallel.
void	par_each (auto &&func) const
	Runs a function on every entity that matches the Args requirement in parallel (const version).
auto	chunks () -> decltype(auto)
	Gets the chunks range.
auto	chunks () const -> decltype(auto)
	Gets the const chunks range.

Detailed Description

template<component_reference... Args>
class co_ecs::view< Args >

A view lets you get a range over components of Args out of a registry.

Views represent a slice of a registry restricting the access to a particular components.

co_ecs::view<position&, const velocity&> view{ registry };
 
// Iterate using iterators:
for (auto [pos, vel] : view.each()) {
    pos.x += vel.x;
    pos.y += vel.y;
}
 
// Alternativelly, iterate using a callback
view.each([](auto& pos, const auto& vel) {
    pos.x += vel.x;
    pos.y += vel.y;
});

Note

A view isn't invalidated when there are changes made to the registry, which allows creating one and re-using it over time.

Template Parameters

Args	Component reference types

Constructor & Destructor Documentation

view()

template<component_reference... Args>

co_ecs::view< Args >::view ( registry_type registry )

inlineexplicitnoexcept

Constructs a new view object.

Parameters

registry

Reference to the registry.

Member Function Documentation

chunks() [1/2]

template<component_reference... Args>

auto co_ecs::view< Args >::chunks ( ) -> decltype(auto)

inline

Gets the chunks range.

Returns

Chunks.

chunks() [2/2]

template<component_reference... Args>

auto co_ecs::view< Args >::chunks ( ) const -> decltype(auto)

inline

Gets the const chunks range.

Returns

Chunks.

each() [1/4]

template<component_reference... Args>

auto co_ecs::view< Args >::each ( ) -> decltype(auto) requires(!is_const)

inline

Returns an iterator that yields a std::tuple<Args...>.

Returns

decltype(auto) Iterator.

each() [2/4]

template<component_reference... Args>

auto co_ecs::view< Args >::each ( ) const -> decltype(auto) requires(is_const)

inline

Returns an iterator that yields a std::tuple<Args...> (const version).

Returns

decltype(auto) Iterator.

each() [3/4]

template<component_reference... Args>

void co_ecs::view< Args >::each ( auto && func )

inline

Runs a function on every entity that matches the Args requirement.

Parameters

func	A callable to run on entity components.

each() [4/4]

template<component_reference... Args>

void co_ecs::view< Args >::each ( auto && func ) const

inline

Runs a function on every entity that matches the Args requirement (const version).

Parameters

func	A callable to run on entity components.

Note

This method is similar to the non-const each() but is available in const views.

par_each() [1/2]

template<component_reference... Args>

void co_ecs::view< Args >::par_each ( auto && func )

inline

Runs a function on every entity that matches the Args requirement in parallel.

Parameters

func	A callable to run on entity components.

par_each() [2/2]

template<component_reference... Args>

void co_ecs::view< Args >::par_each ( auto && func ) const

inline

Runs a function on every entity that matches the Args requirement in parallel (const version).

Parameters

func	A callable to run on entity components.

Note

This method is similar to the non-const par_each() but is available in const views.

single() [1/2]

template<component_reference... Args>

auto co_ecs::view< Args >::single ( ) -> std::optional<std::tuple<Args...>> requires(!is_const)

inline

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

This method is available in const views 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.

co_ecs::view<directional_light&> view{ registry };
// Only one instance with directional_light component is supported
auto [dir_light] = *view.single();

Returns

Optional tuple of components if found, otherwise empty optional.

single() [2/2]

template<component_reference... Args>

auto co_ecs::view< Args >::single ( ) const -> std::optional<std::tuple<Args...>> requires(is_const)

inline

Returns a single tuple of components matching Args, if available in the view (const version).

Returns

Optional tuple of components if found, otherwise empty optional.

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

• include/co_ecs/view.hpp