Iterator for query results with entity information. More...

#include <query.hpp>

Inheritance diagram for helios::ecs::details::QueryWithEntityIterator< Components >:

Public Types
using	ComponentsType = std::conditional_t< AllComponentsConst< Components... >, const details::Components, details::Components >
	Components manager type based on whether all components are const-qualified.

using	iterator_category = std::forward_iterator_tag

using	value_type = std::tuple< Entity, ComponentAccessType< Components >... >

using	difference_type = ptrdiff_t

using	pointer = value_type *

using	reference = value_type

Public Member Functions
	QueryWithEntityIterator (std::span< const std::reference_wrapper< const Archetype > > archetypes, ComponentsType &components, size_t archetype_index=0, size_t entity_index=0)
	Constructs iterator for query results with entity.

	QueryWithEntityIterator (const QueryWithEntityIterator &) noexcept=default

	QueryWithEntityIterator (QueryWithEntityIterator &&) noexcept=default

	~QueryWithEntityIterator () noexcept=default

QueryWithEntityIterator &	operator= (const QueryWithEntityIterator &) noexcept=default

QueryWithEntityIterator &	operator= (QueryWithEntityIterator &&) noexcept=default

QueryWithEntityIterator &	operator++ ()
	Advances iterator to next matching entity.

QueryWithEntityIterator	operator++ (int)
	Advances iterator to next matching entity.

QueryWithEntityIterator &	operator-- ()
	Moves iterator to previous matching entity.

QueryWithEntityIterator	operator-- (int)
	Moves iterator to previous matching entity.

value_type	operator* () const
	Dereferences iterator to get entity and component tuple.

bool	operator== (const QueryWithEntityIterator &other) const noexcept
	Compares iterators for equality.

bool	operator!= (const QueryWithEntityIterator &other) const noexcept
	Compares iterators for inequality.

QueryWithEntityIterator	begin () const noexcept
	Returns iterator to the beginning.

QueryWithEntityIterator	end () const noexcept
	Returns iterator to the end.

Detailed Description

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>
class helios::ecs::details::QueryWithEntityIterator< Components >

Iterator for query results with entity information.

Provides forward iteration over entities matching the query criteria, returning tuples that include the entity followed by requested component references.

Note: Not thread-safe.

Template Parameters

Components Requested component access types (may include const qualifiers)

Definition at line 249 of file query.hpp.

Member Typedef Documentation

◆ ComponentsType

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::ComponentsType = std::conditional_t<AllComponentsConst<Components...>, const details::Components, details::Components>

Components manager type based on whether all components are const-qualified.

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 252 of file query.hpp.

◆ difference_type

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::difference_type = ptrdiff_t

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 258 of file query.hpp.

◆ iterator_category

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::iterator_category = std::forward_iterator_tag

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 256 of file query.hpp.

◆ pointer

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::pointer = value_type*

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 259 of file query.hpp.

◆ reference

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::reference = value_type

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 260 of file query.hpp.

◆ value_type

template<ComponentTrait... Components>

using helios::ecs::details::QueryWithEntityIterator< Components >::value_type = std::tuple<Entity, ComponentAccessType<Components>...>

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 257 of file query.hpp.

Constructor & Destructor Documentation

◆ QueryWithEntityIterator() [1/3]

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

helios::ecs::details::QueryWithEntityIterator< Components >::QueryWithEntityIterator	(	std::span< const std::reference_wrapper< const Archetype > >	archetypes,
		ComponentsType &	components,
		size_t	archetype_index = `0`,
		size_t	entity_index = `0`
	)

Constructs iterator for query results with entity.

Initializes iterator to point to the first matching entity.

Parameters

archetypes	Span of archetypes matching the query
components	Component manager for accessing component data
archetype_index	Starting archetype index (default: 0)
entity_index	Starting entity index within archetype (default: 0)

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 453 of file query.hpp.

    : archetypes_(archetypes), components_(components), archetype_index_(archetype_index), entity_index_(entity_index) {
  AdvanceToValidEntity();
}

◆ QueryWithEntityIterator() [2/3]

template<ComponentTrait... Components>

helios::ecs::details::QueryWithEntityIterator< Components >::QueryWithEntityIterator ( const QueryWithEntityIterator< Components > & )

defaultnoexcept

◆ QueryWithEntityIterator() [3/3]

template<ComponentTrait... Components>

helios::ecs::details::QueryWithEntityIterator< Components >::QueryWithEntityIterator ( QueryWithEntityIterator< Components > && )

defaultnoexcept

◆ ~QueryWithEntityIterator()

template<ComponentTrait... Components>

helios::ecs::details::QueryWithEntityIterator< Components >::~QueryWithEntityIterator ( )

defaultnoexcept

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Member Function Documentation

◆ begin()

template<ComponentTrait... Components>

QueryWithEntityIterator helios::ecs::details::QueryWithEntityIterator< Components >::begin ( ) const

inlinenoexcept

Returns iterator to the beginning.

Returns: Copy of this iterator

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 331 of file query.hpp.

331{ return *this; }

◆ end()

template<ComponentTrait... Components>

QueryWithEntityIterator helios::ecs::details::QueryWithEntityIterator< Components >::end ( ) const

inlinenoexcept

Returns iterator to the end.

Returns: End iterator

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 337 of file query.hpp.

                                                             {
    return {archetypes_, components_.get(), archetypes_.size(), 0};
  }

◆ operator!=()

template<ComponentTrait... Components>

bool helios::ecs::details::QueryWithEntityIterator< Components >::operator!= ( const QueryWithEntityIterator< Components > & other ) const

inlinenoexcept

Compares iterators for inequality.

Parameters

other Iterator to compare with

Returns: True if iterators are not equal, false otherwise

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 325 of file query.hpp.

325{ return !(*this == other); }

◆ operator*()

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

auto helios::ecs::details::QueryWithEntityIterator< Components >::operator* ( ) const

inline

Dereferences iterator to get entity and component tuple.

Returns tuple starting with entity followed by component references.

Warning: Triggers assertion if iterator is at end or in invalid state.

Returns: Tuple of entity and component references

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 514 of file query.hpp.

                                                                                  {
  HELIOS_ASSERT(!IsAtEnd(), "Cannot dereference end iterator!");
  HELIOS_ASSERT(archetype_index_ < archetypes_.size(), "Archetype index out of bounds!");
  HELIOS_ASSERT(entity_index_ < archetypes_[archetype_index_].get().Entities().size(), "Entity index out of bounds!");
 
  const auto& archetype = archetypes_[archetype_index_].get();
  const Entity entity = archetype.Entities()[entity_index_];
 
  return {entity,
          [&]<typename ComponentType = ComponentTypeExtractor_t<Components>>() -> ComponentAccessType<Components> {
            return static_cast<ComponentAccessType<Components>>(
                components_.get().template GetComponent<ComponentType>(entity));
          }()...};
}

◆ operator++() [1/2]

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

auto helios::ecs::details::QueryWithEntityIterator< Components >::operator++ ( )

inline

Advances iterator to next matching entity.

Returns: Reference to this iterator after advancement

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 462 of file query.hpp.

                                                                                           {
  ++entity_index_;
  AdvanceToValidEntity();
  return *this;
}

◆ operator++() [2/2]

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

auto helios::ecs::details::QueryWithEntityIterator< Components >::operator++ ( int )

inline

Advances iterator to next matching entity.

Returns: Copy of iterator before advancement

Definition at line 470 of file query.hpp.

                                                                                             {
  auto copy = *this;
  ++(*this);
  return copy;
}

◆ operator--() [1/2]

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

auto helios::ecs::details::QueryWithEntityIterator< Components >::operator-- ( )

inline

Moves iterator to previous matching entity.

Returns: Reference to this iterator after moving backward

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 478 of file query.hpp.

                                                                                           {
  // If at end or beginning of current archetype, need to go back
  while (true) {
    if (entity_index_ > 0) {
      --entity_index_;
      return *this;
    }
 
    // Need to move to previous archetype
    if (archetype_index_ == 0) {
      // Already at beginning, can't go back further
      return *this;
    }
 
    --archetype_index_;
    // Move to last entity in previous archetype
    if (archetype_index_ < archetypes_.size()) {
      entity_index_ = archetypes_[archetype_index_].get().EntityCount();
      if (entity_index_ > 0) {
        --entity_index_;
        return *this;
      }
    }
  }
}

◆ operator--() [2/2]

template<ComponentTrait... Components>
requires utils::UniqueTypes<Components...>

auto helios::ecs::details::QueryWithEntityIterator< Components >::operator-- ( int )

inline

Moves iterator to previous matching entity.

Returns: Copy of iterator before moving backward

Definition at line 506 of file query.hpp.

                                                                                             {
  auto copy = *this;
  --(*this);
  return copy;
}

◆ operator=() [1/2]

template<ComponentTrait... Components>

QueryWithEntityIterator & helios::ecs::details::QueryWithEntityIterator< Components >::operator= ( const QueryWithEntityIterator< Components > & )

defaultnoexcept

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

◆ operator=() [2/2]

template<ComponentTrait... Components>

QueryWithEntityIterator & helios::ecs::details::QueryWithEntityIterator< Components >::operator= ( QueryWithEntityIterator< Components > && )

defaultnoexcept

◆ operator==()

template<ComponentTrait... Components>

bool helios::ecs::details::QueryWithEntityIterator< Components >::operator== ( const QueryWithEntityIterator< Components > & other ) const

inlinenoexcept

Compares iterators for equality.

Parameters

other Iterator to compare with

Returns: True if iterators are equal, false otherwise

Examples: /home/runner/work/HeliosEngine/HeliosEngine/src/core/include/helios/core/ecs/query.hpp.

Definition at line 316 of file query.hpp.

                                                                                     {
    return archetype_index_ == other.archetype_index_ && entity_index_ == other.entity_index_;
  }

	Helios Engine 0.1.0 A modular ECS based data-oriented C++23 game engine

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ ComponentsType

◆ difference_type

◆ iterator_category

◆ pointer

◆ reference

◆ value_type

Constructor & Destructor Documentation

◆ QueryWithEntityIterator() [1/3]

◆ QueryWithEntityIterator() [2/3]

◆ QueryWithEntityIterator() [3/3]

◆ ~QueryWithEntityIterator()

Member Function Documentation

◆ begin()

◆ end()

◆ operator!=()

◆ operator*()

◆ operator++() [1/2]

◆ operator++() [2/2]

◆ operator--() [1/2]

◆ operator--() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()