System Class

Type-erased wrapper for game logic processors. More...

Declaration

class helios::engine::runtime::world::System { ... }

Public Constructors Index

	System ()=default
	Default constructor creating an empty System. More...
template <typename T>
System (T system)
	Wraps a concrete system in a type-erased System. More...
	System (const System &)=delete
	System (System &&) noexcept=default

Public Operators Index

System &	operator= (const System &)=delete
System &	operator= (System &&)=default

Public Member Functions Index

void	update (UpdateContext &updateContext) noexcept
	Delegates to the wrapped system's `update()` method. More...
void	init (GameWorld &gameWorld) noexcept
	Delegates to the wrapped system's `init()` method, if present. More...
void *	underlying () noexcept
	Returns a type-erased pointer to the wrapped system instance. More...
const void *	underlying () const noexcept
	Returns a type-erased pointer to the wrapped system instance. More...

Private Member Attributes Index

std::unique_ptr< Concept >	pimpl_

Description

Type-erased wrapper for game logic processors.

System uses the Concept/Model pattern to erase the concrete system type. Concrete systems are plain classes that satisfy `HasUpdate<T>` — they do not inherit from System.

The internal `Concept` base defines the virtual interface, and `Model<T>` adapts the concrete type T, owning it by value. `init()` is conditionally forwarded if `HasInit<T>` is satisfied.

System is move-only (non-copyable).

See Also

HasUpdate

See Also

HasInit

See Also

SystemRegistry

See Also

https://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Type_Erasure

Definition at line 43 of file System.ixx.

Public Constructors

System()

helios::engine::runtime::world::System::System ()

default

Default constructor creating an empty System.

Definition at line 98 of file System.ixx.

Referenced by operator=, operator=, System and System.

System()

template <typename T>

helios::engine::runtime::world::System::System (T system)

inline explicit

Wraps a concrete system in a type-erased System.

Template Parameters

T	The concrete system type, must satisfy `HasUpdate<T>`.

Parameters

system

The concrete system instance to wrap (moved into internal storage).

Definition at line 109 of file System.ixx.

109 explicit System(T system) : pimpl_(std::make_unique<Model<T>>(std::move(system))) {}

System()

helios::engine::runtime::world::System::System (const System &)

delete

Definition at line 111 of file System.ixx.

Reference System.

System()

helios::engine::runtime::world::System::System (System &&)

noexcept default

Definition at line 115 of file System.ixx.

Reference System.

Public Operators

operator=()

System & helios::engine::runtime::world::System::operator= (const System &)

delete

Definition at line 112 of file System.ixx.

Reference System.

operator=()

System & helios::engine::runtime::world::System::operator= (System &&)

default

Definition at line 114 of file System.ixx.

Reference System.

Public Member Functions

init()

void helios::engine::runtime::world::System::init (GameWorld & gameWorld)

inline noexcept

Delegates to the wrapped system's `init()` method, if present.

If the concrete type satisfies `HasInit<T>`, its `init()` is called. Otherwise this is a no-op.

Parameters

gameWorld

The GameWorld for one-time initialization.

Precondition

System must be initialized (pimpl_ != nullptr).

Definition at line 140 of file System.ixx.

140 void init(GameWorld& gameWorld) noexcept {

141 assert(pimpl_ && "System not initialized");

142 pimpl_->init(gameWorld);

143 }

underlying()

void * helios::engine::runtime::world::System::underlying ()

inline nodiscard noexcept

Returns a type-erased pointer to the wrapped system instance.

Returns

Pointer to the underlying concrete system.

Precondition

System must be initialized (pimpl_ != nullptr).

Definition at line 152 of file System.ixx.

152 [[nodiscard]] void* underlying() noexcept {

153 assert(pimpl_ && "System not initialized");

154 return pimpl_->underlying();

155 }

underlying()

const void * helios::engine::runtime::world::System::underlying ()

inline nodiscard noexcept

Returns a type-erased pointer to the wrapped system instance.

Returns

Pointer to the underlying concrete system.

Precondition

System must be initialized (pimpl_ != nullptr).

Definition at line 160 of file System.ixx.

160 [[nodiscard]] const void* underlying() const noexcept {

161 assert(pimpl_ && "System not initialized");

162 return pimpl_->underlying();

163 }

update()

void helios::engine::runtime::world::System::update (UpdateContext & updateContext)

inline noexcept

Delegates to the wrapped system's `update()` method.

Parameters

updateContext

The current frame's update context.

Precondition

System must be initialized (pimpl_ != nullptr).

Definition at line 125 of file System.ixx.

125 void update(UpdateContext& updateContext) noexcept {

126 assert(pimpl_ && "System not initialized");

127 pimpl_->update(updateContext);

128 }

Reference update.

Referenced by update.

Private Member Attributes

pimpl_

std::unique_ptr<Concept> helios::engine::runtime::world::System::pimpl_

Definition at line 91 of file System.ixx.

91 std::unique_ptr<Concept> pimpl_;

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

• System.ixx

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