Iterator Struct

Forward iterator for View traversal. More...

Declaration

struct helios::ecs::View::Iterator { ... }

Public Member Typedefs Index

using	Entity_type = Entity< TEntityManager >
using	LeadComponent = std::tuple_element_t< 0, std::tuple< Components... > >
	The first component type determines iteration order. More...
using	LeadIterator = typename SparseSet< LeadComponent >::Iterator
	Iterator type from the lead component's SparseSet. More...

Public Constructors Index

	Iterator ()=default
	Default constructor creating an invalid iterator. More...
	Iterator (LeadIterator current, LeadIterator end, const View *view)
	Constructs an iterator with the given range and view. More...

Public Operators Index

Iterator &	operator++ () noexcept
	Pre-increment operator. More...
bool	operator!= (const Iterator &other) const noexcept
	Inequality comparison. More...
auto	operator* () const
	Dereference operator. More...
bool	operator== (const Iterator &other) const noexcept

Public Member Functions Index

bool	isValid () const
	Validates if the current entity matches all filter criteria. More...
void	advance ()
	Advances to the next valid entity. More...

Public Member Attributes Index

LeadIterator	current_
LeadIterator	end_
const View *	view_

Description

Forward iterator for View traversal.

Uses the first component type as the "lead" iterator and validates each entity against all include/exclude/enabled criteria before yielding.

Definition at line 146 of file View.ixx.

Public Member Typedefs

Entity_type

using helios::ecs::View< TEntityManager, Components >::Iterator::Entity_type = Entity<TEntityManager>

Definition at line 148 of file View.ixx.

148 using Entity_type = Entity<TEntityManager>;

LeadComponent

using helios::ecs::View< TEntityManager, Components >::Iterator::LeadComponent = std::tuple_element_t<0, std::tuple<Components...>>

The first component type determines iteration order.

Definition at line 153 of file View.ixx.

153 using LeadComponent = std::tuple_element_t<0, std::tuple<Components...>>;

LeadIterator

using helios::ecs::View< TEntityManager, Components >::Iterator::LeadIterator = typename SparseSet<LeadComponent>::Iterator

Iterator type from the lead component's SparseSet.

Definition at line 158 of file View.ixx.

158 using LeadIterator = typename SparseSet<LeadComponent>::Iterator;

Public Constructors

Iterator()

helios::ecs::View< TEntityManager, Components >::Iterator::Iterator ()

default

Default constructor creating an invalid iterator.

Definition at line 167 of file View.ixx.

Referenced by helios::ecs::View< TEntityManager, Components >::Iterator::operator!=, helios::ecs::View< TEntityManager, Components >::Iterator::operator++ and helios::ecs::View< TEntityManager, Components >::Iterator::operator==.

Iterator()

helios::ecs::View< TEntityManager, Components >::Iterator::Iterator (LeadIterator current, LeadIterator end, const View * view)

inline

Constructs an iterator with the given range and view.

Parameters

current	Iterator to the current position.
end	Iterator to the end position.
view	Pointer to the owning View for filter access.

Definition at line 176 of file View.ixx.

176 Iterator(LeadIterator current, LeadIterator end, const View* view)

177 : current_(current), end_(end), view_(view) {}

References helios::ecs::View< TEntityManager, Components >::Iterator::current_, helios::ecs::View< TEntityManager, Components >::end, helios::ecs::View< TEntityManager, Components >::Iterator::end_, helios::ecs::View< TEntityManager, Components >::View and helios::ecs::View< TEntityManager, Components >::Iterator::view_.

Public Operators

operator!=()

bool helios::ecs::View< TEntityManager, Components >::Iterator::operator!= (const Iterator & other)

inline noexcept

Inequality comparison.

Parameters

other

The iterator to compare against.

Returns

True if iterators point to different positions.

Definition at line 279 of file View.ixx.

279 bool operator!=(const Iterator& other) const noexcept {

280 return current_ != other.current_;

281 }

References helios::ecs::View< TEntityManager, Components >::Iterator::current_ and helios::ecs::View< TEntityManager, Components >::Iterator::Iterator.

operator*()

auto helios::ecs::View< TEntityManager, Components >::Iterator::operator* ()

inline nodiscard

Dereference operator.

Returns

A tuple containing {GameObject, Component*...}.

info

Returns by value to support C++17 Structured Binding (auto [go, comp] : view).

Definition at line 290 of file View.ixx.

290 [[nodiscard]] auto operator*() const {

291 EntityId entityId = current_.entityId();

292

293 auto handle = view_->em_->handle(entityId);

294

295

296 return std::tuple_cat(

297 std::make_tuple(Entity_type(handle, view_->em_)),

298 std::apply([entityId](auto*... sets) {

299 return std::make_tuple(sets->get(entityId)...);

300 }, view_->includeSets_)

301 );

302 }

References helios::ecs::View< TEntityManager, Components >::Iterator::current_ and helios::ecs::View< TEntityManager, Components >::Iterator::view_.

operator++()

Iterator & helios::ecs::View< TEntityManager, Components >::Iterator::operator++ ()

inline noexcept

Pre-increment operator.

Returns

Reference to this iterator after advancing.

Definition at line 267 of file View.ixx.

267 Iterator& operator++() noexcept {

268 advance();

269 return *this;

270 }

References helios::ecs::View< TEntityManager, Components >::Iterator::advance and helios::ecs::View< TEntityManager, Components >::Iterator::Iterator.

operator==()

bool helios::ecs::View< TEntityManager, Components >::Iterator::operator== (const Iterator & other)

inline nodiscard noexcept

Definition at line 304 of file View.ixx.

304 [[nodiscard]] bool operator==(const Iterator& other) const noexcept {

305 return current_ == other.current_;

306 }

References helios::ecs::View< TEntityManager, Components >::Iterator::current_ and helios::ecs::View< TEntityManager, Components >::Iterator::Iterator.

Public Member Functions

advance()

void helios::ecs::View< TEntityManager, Components >::Iterator::advance ()

inline

Advances to the next valid entity.

Increments the underlying iterator and skips invalid entities until a valid one is found or end is reached.

Definition at line 256 of file View.ixx.

256 void advance() {

257 do {

258 ++current_;

259 } while (current_ != end_ && !isValid());

260 }

References helios::ecs::View< TEntityManager, Components >::Iterator::current_, helios::ecs::View< TEntityManager, Components >::Iterator::end_ and helios::ecs::View< TEntityManager, Components >::Iterator::isValid.

Referenced by helios::ecs::View< TEntityManager, Components >::begin and helios::ecs::View< TEntityManager, Components >::Iterator::operator++.

isValid()

bool helios::ecs::View< TEntityManager, Components >::Iterator::isValid ()

inline nodiscard

Validates if the current entity matches all filter criteria.

Performs the following checks in order: 1. Entity validity in the registry 2. Include check - entity has all required components 3. Exclude check - entity has none of the excluded components 4. Enabled check - all components pass isEnabled() (if filtered)

Returns

True if the entity passes all checks, false otherwise.

Definition at line 190 of file View.ixx.

190 [[nodiscard]] bool isValid() const {

191 if (current_ == end_) {

192 return true;

193 }

194

195 // 1 Get Entity ID (from the Lead Iterator)

196 EntityId entityId = current_.entityId();

197

198 if (!view_->em_->isValid(entityId)) {

199 return false;

200 }

201

202 // 2 INCLUDE CHECK (Do we have all other required components?)

203 // We iterate over the tuple of sets and check 'contains' for each.

204 bool hasAllIncludes = std::apply([entityId](auto*... sets) {

205 return ((sets && sets->contains(entityId)) && ...);

206 }, view_->includeSets_);

207

208 if (!hasAllIncludes) {

209 return false;

210 }

211

212 // 3 EXCLUDE CHECK (Must NOT be present)

213 for (const auto& excludeCheck : view_->excludeChecks_) {

214 if (excludeCheck(entityId)) {

215 return false; // If check returns true (has component), the entity is invalid.

216 }

217 }

218

219 // 4 ENABLED CHECK (State)

220 if (view_->filterEnabledOnly_) {

221

222 // SFINAE Helper Lambda: Checks if .isEnabled() exists.

223 auto isComponentEnabled = [](const auto& comp) -> bool {

224 if constexpr (requires { comp.isEnabled(); }) {

225 return comp.isEnabled();

226 } else {

227 return true; // Assume enabled if method is missing.

228 }

229 };

230

231 // Check the Lead component (*current_ returns the component reference)

232 if (!isComponentEnabled(*current_)) {

233 return false;

234 }

235

236 // Check all other included components

237 bool allEnabled = std::apply([&](auto*... sets) {

238 // sets->get(id) returns a pointer, *ptr gives the reference.

239 return (isComponentEnabled(*sets->get(entityId)) && ...);

240 }, view_->includeSets_);

241

242 if (!allEnabled) {

243 return false;

244 }

245 }

246

247 return true;

248 }

References helios::ecs::View< TEntityManager, Components >::Iterator::current_, helios::ecs::View< TEntityManager, Components >::Iterator::end_ and helios::ecs::View< TEntityManager, Components >::Iterator::view_.

Referenced by helios::ecs::View< TEntityManager, Components >::Iterator::advance and helios::ecs::View< TEntityManager, Components >::begin.

Public Member Attributes

current_

LeadIterator helios::ecs::View< TEntityManager, Components >::Iterator::current_

Definition at line 160 of file View.ixx.

160 LeadIterator current_;

Referenced by helios::ecs::View< TEntityManager, Components >::Iterator::advance, helios::ecs::View< TEntityManager, Components >::Iterator::isValid, helios::ecs::View< TEntityManager, Components >::Iterator::Iterator, helios::ecs::View< TEntityManager, Components >::Iterator::operator!=, helios::ecs::View< TEntityManager, Components >::Iterator::operator* and helios::ecs::View< TEntityManager, Components >::Iterator::operator==.

end_

LeadIterator helios::ecs::View< TEntityManager, Components >::Iterator::end_

Definition at line 161 of file View.ixx.

161 LeadIterator end_;

Referenced by helios::ecs::View< TEntityManager, Components >::Iterator::advance, helios::ecs::View< TEntityManager, Components >::Iterator::isValid and helios::ecs::View< TEntityManager, Components >::Iterator::Iterator.

view_

const View* helios::ecs::View< TEntityManager, Components >::Iterator::view_

Definition at line 162 of file View.ixx.

162 const View* view_;

Referenced by helios::ecs::View< TEntityManager, Components >::Iterator::isValid, helios::ecs::View< TEntityManager, Components >::Iterator::Iterator and helios::ecs::View< TEntityManager, Components >::Iterator::operator*.

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

• View.ixx

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