Queue for managing multiple message types using type-erased contiguous storage. More...

#include <queue.hpp>

Public Types
using	size_type = MessageStorage::size_type
using	allocator_type = MessageStorage::allocator_type

Public Member Functions
constexpr	MessageQueue ()=default
constexpr	MessageQueue (const allocator_type &alloc)
	Constructs an MessageQueue with a custom allocator.
constexpr	MessageQueue (std::pmr::memory_resource *resource)
	Constructs a MessageQueue from a PMR memory resource.
	MessageQueue (std::nullptr_t)=delete
constexpr	MessageQueue (const MessageQueue &)=default
constexpr	MessageQueue (MessageQueue &&) noexcept=default
constexpr	~MessageQueue ()=default
constexpr MessageQueue &	operator= (const MessageQueue &)=default
constexpr MessageQueue &	operator= (MessageQueue &&) noexcept=default
template<MessageTrait T>
constexpr void	Register ()
	Registers an message type with the queue.
constexpr void	Register (MessageTypeIndex type_index)
	Ensures storage exists for the given runtime type index.
constexpr void	ClearAll () noexcept
	Clears all messages from the queue maintaining all registered types.
template<MessageTrait T>
constexpr void	Clear () noexcept
	Clears messages of a specific type.
constexpr void	Clear (MessageTypeIndex type_index) noexcept
	Clears messages of a specific type by runtime type index.
constexpr void	ResetAll () noexcept
	Resets the queue by clearing all messages and unregistering all types.
template<MessageTrait T>
constexpr void	Reset () noexcept
	Resets a specific message type by clearing its messages and unregistering the type.
template<typename OtherAllocator>
constexpr void	Merge (const MessageQueue< OtherAllocator > &other)
	Merges messages from another MessageQueue into this one.
template<typename OtherAllocator>
constexpr void	Merge (MessageQueue< OtherAllocator > &&other)
	Merges messages from another MessageQueue into this one.
template<MessageTrait T>
void	Enqueue (T &&message)
	Enqueues an message into the queue.
template<std::ranges::input_range R> requires MessageTrait<std::ranges::range_value_t<R>>
void	EnqueueBulk (R &&messages)
	Enqueues multiple messages in bulk.
template<MessageTrait T>
void	RemoveIndices (std::span< const size_type > sorted_indices)
	Removes messages at the given sorted indices for a specific message type.
void	RemoveIndices (MessageTypeIndex type_index, std::span< const size_type > sorted_indices)
	Removes messages at the given sorted indices for a specific type.
constexpr void	Swap (MessageQueue &other) noexcept
	Swaps the contents of this queue with another.
template<MessageTrait T>
constexpr bool	IsRegistered () const noexcept
	Checks if an message type is registered.
constexpr bool	IsRegistered (MessageTypeIndex type_index) const noexcept
	Checks if an message type is registered by runtime type index.
constexpr bool	HasMessages () const noexcept
	Checks if any messages exist in the queue across all types.
template<MessageTrait T>
constexpr bool	HasMessages () const noexcept
	Checks if messages of a specific type exist in the queue.
template<MessageTrait T>
constexpr auto	Messages () const noexcept -> std::span< const T >
	Gets a const span of all messages of a specific type.
template<MessageTrait T>
constexpr auto	Messages () noexcept -> std::span< T >
	Gets a mutable span of all messages of a specific type.
constexpr size_type	TypeCount () const noexcept
	Gets the number of message types stored.
constexpr size_type	MessageCount () const noexcept
	Gets the total number of messages stored across all types.
template<MessageTrait T>
constexpr size_type	MessageCount () const noexcept
	Gets the total number of messages stored for a specific message type.
constexpr size_type	MessageCount (MessageTypeIndex type_index) const noexcept
	Gets the number of messages for a type by runtime type index.

Friends
template<typename OtherAllocator>
class	MessageQueue
constexpr void	swap (MessageQueue &lhs, MessageQueue &rhs) noexcept
	Swaps the contents of two message queues.

Detailed Description

template<typename Allocator = std::allocator<std::byte>>
class helios::ecs::MessageQueue< Allocator >

Queue for managing multiple message types using type-erased contiguous storage.

Messages are stored in a MultiTypeBuffer, which provides per-type contiguous storage.

Note: Not thread-safe.

Template Parameters

Allocator Allocator type for internal storage (default: std::allocator<std::byte>)

Definition at line 26 of file queue.hpp.

Member Typedef Documentation

◆ allocator_type

template<typename Allocator = std::allocator<std::byte>>

using helios::ecs::MessageQueue< Allocator >::allocator_type = MessageStorage::allocator_type

Definition at line 34 of file queue.hpp.

◆ size_type

template<typename Allocator = std::allocator<std::byte>>

using helios::ecs::MessageQueue< Allocator >::size_type = MessageStorage::size_type

Definition at line 33 of file queue.hpp.

Constructor & Destructor Documentation

◆ MessageQueue() [1/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( )

constexprdefault

◆ MessageQueue() [2/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( const allocator_type & alloc )

inlineexplicitconstexpr

Constructs an MessageQueue with a custom allocator.

Parameters

alloc Allocator instance

Definition at line 42 of file queue.hpp.

◆ MessageQueue() [3/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( std::pmr::memory_resource * resource )

inlineexplicitconstexpr

Constructs a MessageQueue from a PMR memory resource.

Enabled only when allocator_type is constructible from std::pmr::memory_resource*.

Parameters

resource Memory resource used to construct allocator

Definition at line 51 of file queue.hpp.

◆ MessageQueue() [4/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( std::nullptr_t )

delete

◆ MessageQueue() [5/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( const MessageQueue< Allocator > & )

constexprdefault

◆ MessageQueue() [6/6]

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::MessageQueue ( MessageQueue< Allocator > && )

constexprdefaultnoexcept

◆ ~MessageQueue()

template<typename Allocator = std::allocator<std::byte>>

helios::ecs::MessageQueue< Allocator >::~MessageQueue ( )

constexprdefault

Member Function Documentation

◆ Clear() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

void helios::ecs::MessageQueue< Allocator >::Clear ( )

inlineconstexprnoexcept

Clears messages of a specific type.

Template Parameters

T	Message type

Definition at line 93 of file queue.hpp.

◆ Clear() [2/2]

template<typename Allocator = std::allocator<std::byte>>

void helios::ecs::MessageQueue< Allocator >::Clear ( MessageTypeIndex type_index )

inlineconstexprnoexcept

Clears messages of a specific type by runtime type index.

Parameters

type_index Type index of messages to clear

Definition at line 101 of file queue.hpp.

◆ ClearAll()

template<typename Allocator = std::allocator<std::byte>>

void helios::ecs::MessageQueue< Allocator >::ClearAll ( )

inlineconstexprnoexcept

Clears all messages from the queue maintaining all registered types.

Definition at line 86 of file queue.hpp.

◆ Enqueue()

template<typename Allocator>

template<MessageTrait T>

void helios::ecs::MessageQueue< Allocator >::Enqueue ( T && message )

inline

Enqueues an message into the queue.

Warning: Triggers assertion if message type is not registered.

Template Parameters

T	Message type

Parameters

message Message to enqueue

Definition at line 312 of file queue.hpp.

◆ EnqueueBulk()

template<typename Allocator>
requires MessageTrait<std::ranges::range_value_t<R>>

template<std::ranges::input_range R>
requires MessageTrait<std::ranges::range_value_t<R>>

void helios::ecs::MessageQueue< Allocator >::EnqueueBulk ( R && messages )

inline

Enqueues multiple messages in bulk.

Warning: Triggers assertion if message type is not registered.

Template Parameters

R	Range type

Parameters

messages Range of messages to enqueue

Definition at line 323 of file queue.hpp.

◆ HasMessages() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

bool helios::ecs::MessageQueue< Allocator >::HasMessages ( ) const

inlinenodiscardconstexprnoexcept

Checks if messages of a specific type exist in the queue.

Template Parameters

T	Message type

Returns: True if messages of type T exist, false otherwise or if the type is not registered

Definition at line 238 of file queue.hpp.

◆ HasMessages() [2/2]

template<typename Allocator = std::allocator<std::byte>>

bool helios::ecs::MessageQueue< Allocator >::HasMessages ( ) const

inlinenodiscardconstexprnoexcept

Checks if any messages exist in the queue across all types.

Returns: True if at least one message exists, false otherwise

Definition at line 227 of file queue.hpp.

◆ IsRegistered() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

bool helios::ecs::MessageQueue< Allocator >::IsRegistered ( ) const

inlinenodiscardconstexprnoexcept

Checks if an message type is registered.

Template Parameters

T	Message type

Returns: True if the message type is registered, false otherwise

Definition at line 209 of file queue.hpp.

◆ IsRegistered() [2/2]

template<typename Allocator = std::allocator<std::byte>>

bool helios::ecs::MessageQueue< Allocator >::IsRegistered ( MessageTypeIndex type_index ) const

inlinenodiscardconstexprnoexcept

Checks if an message type is registered by runtime type index.

Parameters

type_index Type index to check

Returns: True if the message type is registered, false otherwise

Definition at line 218 of file queue.hpp.

◆ Merge() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<typename OtherAllocator>

void helios::ecs::MessageQueue< Allocator >::Merge ( const MessageQueue< OtherAllocator > & other )

inlineconstexpr

Merges messages from another MessageQueue into this one.

For each type in other, messages are appended to the corresponding storage in this queue. After merging, other is left in a valid but empty state.

Template Parameters

OtherAllocator Allocator template of the other queue

Parameters

other MessageQueue to merge from

Definition at line 128 of file queue.hpp.

◆ Merge() [2/2]

template<typename Allocator = std::allocator<std::byte>>

template<typename OtherAllocator>

void helios::ecs::MessageQueue< Allocator >::Merge ( MessageQueue< OtherAllocator > && other )

inlineconstexpr

Merges messages from another MessageQueue into this one.

Rvalue overload that consumes the source queue.

Template Parameters

OtherAllocator Allocator template of the other queue

Parameters

other MessageQueue to merge from

Definition at line 139 of file queue.hpp.

◆ MessageCount() [1/3]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

size_type helios::ecs::MessageQueue< Allocator >::MessageCount ( ) const

inlinenodiscardconstexprnoexcept

Gets the total number of messages stored for a specific message type.

Template Parameters

T	Message type

Returns: Total message count or 0 if the type is not registered

Definition at line 289 of file queue.hpp.

◆ MessageCount() [2/3]

template<typename Allocator = std::allocator<std::byte>>

size_type helios::ecs::MessageQueue< Allocator >::MessageCount ( ) const

inlinenodiscardconstexprnoexcept

Gets the total number of messages stored across all types.

Returns: Total message count or 0 if no types are registered

Definition at line 278 of file queue.hpp.

◆ MessageCount() [3/3]

template<typename Allocator = std::allocator<std::byte>>

size_type helios::ecs::MessageQueue< Allocator >::MessageCount ( MessageTypeIndex type_index ) const

inlinenodiscardconstexprnoexcept

Gets the number of messages for a type by runtime type index.

Parameters

type_index Type index to query

Returns: Number of messages, or 0 if the type is not registered

Definition at line 298 of file queue.hpp.

◆ Messages() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

auto helios::ecs::MessageQueue< Allocator >::Messages ( ) const -> std::span< const T >

inlinenodiscardconstexprnoexcept

Gets a const span of all messages of a specific type.

Template Parameters

T	Message type

Returns: Span of const messages, or empty span if type is not registered or has no messages

Definition at line 249 of file queue.hpp.

◆ Messages() [2/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

auto helios::ecs::MessageQueue< Allocator >::Messages ( ) -> std::span< T >

inlinenodiscardconstexprnoexcept

Gets a mutable span of all messages of a specific type.

Template Parameters

T	Message type

Returns: Span of messages, or empty span if type is not registered or has no messages

Definition at line 261 of file queue.hpp.

◆ operator=() [1/2]

template<typename Allocator = std::allocator<std::byte>>

MessageQueue & helios::ecs::MessageQueue< Allocator >::operator= ( const MessageQueue< Allocator > & )

constexprdefault

◆ operator=() [2/2]

template<typename Allocator = std::allocator<std::byte>>

MessageQueue & helios::ecs::MessageQueue< Allocator >::operator= ( MessageQueue< Allocator > && )

constexprdefaultnoexcept

◆ Register() [1/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

void helios::ecs::MessageQueue< Allocator >::Register ( )

inlineconstexpr

Registers an message type with the queue.

Template Parameters

T	Message type

Definition at line 69 of file queue.hpp.

◆ Register() [2/2]

template<typename Allocator = std::allocator<std::byte>>

void helios::ecs::MessageQueue< Allocator >::Register ( MessageTypeIndex type_index )

inlineconstexpr

Ensures storage exists for the given runtime type index.

Used when the concrete type is not available at call-site (e.g., during Update re-registration). If the type index is already registered, this is a no-op.

Parameters

type_index Runtime type index

Definition at line 80 of file queue.hpp.

◆ RemoveIndices() [1/2]

template<typename Allocator>

void helios::ecs::MessageQueue< Allocator >::RemoveIndices	(	MessageTypeIndex	type_index,
		std::span< const size_type >	sorted_indices )

inline

Removes messages at the given sorted indices for a specific type.

Erases messages at the provided sorted, deduplicated indices from back to front to avoid index invalidation. No additional allocation is performed.

Warning: Triggers assertion if type_index is not registered.

Parameters

type_index	Type index of the message type
sorted_indices	Span of sorted, unique global indices to remove

Definition at line 331 of file queue.hpp.

◆ RemoveIndices() [2/2]

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

void helios::ecs::MessageQueue< Allocator >::RemoveIndices ( std::span< const size_type > sorted_indices )

inline

Removes messages at the given sorted indices for a specific message type.

Warning: Triggers assertion if message type is not registered.

Template Parameters

T	Message type

Parameters

sorted_indices Span of sorted, unique global indices to remove

Definition at line 170 of file queue.hpp.

◆ Reset()

template<typename Allocator = std::allocator<std::byte>>

template<MessageTrait T>

void helios::ecs::MessageQueue< Allocator >::Reset ( )

inlineconstexprnoexcept

Resets a specific message type by clearing its messages and unregistering the type.

Template Parameters

T	Message type

Definition at line 115 of file queue.hpp.

◆ ResetAll()

template<typename Allocator = std::allocator<std::byte>>

void helios::ecs::MessageQueue< Allocator >::ResetAll ( )

inlineconstexprnoexcept

Resets the queue by clearing all messages and unregistering all types.

Definition at line 107 of file queue.hpp.

◆ Swap()

template<typename Allocator = std::allocator<std::byte>>

void helios::ecs::MessageQueue< Allocator >::Swap ( MessageQueue< Allocator > & other )

inlineconstexprnoexcept

Swaps the contents of this queue with another.

Parameters

other Another MessageQueue to swap with

Definition at line 190 of file queue.hpp.

◆ TypeCount()

template<typename Allocator = std::allocator<std::byte>>

size_type helios::ecs::MessageQueue< Allocator >::TypeCount ( ) const

inlinenodiscardconstexprnoexcept

Gets the number of message types stored.

Returns: Number of distinct message types

Definition at line 270 of file queue.hpp.

◆ MessageQueue

template<typename Allocator = std::allocator<std::byte>>

template<typename OtherAllocator>

friend class MessageQueue

friend

Definition at line 305 of file queue.hpp.

◆ swap

template<typename Allocator = std::allocator<std::byte>>

void swap	(	MessageQueue< Allocator > &	lhs,
		MessageQueue< Allocator > &	rhs )

friend

Swaps the contents of two message queues.

Parameters

lhs	First MessageQueue
rhs	Second MessageQueue

Definition at line 199 of file queue.hpp.

Public Types

Public Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ allocator_type

◆ size_type

Constructor & Destructor Documentation

◆ MessageQueue() [1/6]

◆ MessageQueue() [2/6]

◆ MessageQueue() [3/6]

◆ MessageQueue() [4/6]

◆ MessageQueue() [5/6]

◆ MessageQueue() [6/6]

◆ ~MessageQueue()

Member Function Documentation

◆ Clear() [1/2]

◆ Clear() [2/2]

◆ ClearAll()

◆ Enqueue()

◆ EnqueueBulk()

◆ HasMessages() [1/2]

◆ HasMessages() [2/2]

◆ IsRegistered() [1/2]

◆ IsRegistered() [2/2]

◆ Merge() [1/2]

◆ Merge() [2/2]

◆ MessageCount() [1/3]

◆ MessageCount() [2/3]

◆ MessageCount() [3/3]

◆ Messages() [1/2]

◆ Messages() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Register() [1/2]

◆ Register() [2/2]

◆ RemoveIndices() [1/2]

◆ RemoveIndices() [2/2]

◆ Reset()

◆ ResetAll()

◆ Swap()

◆ TypeCount()

Friends And Related Symbol Documentation

◆ MessageQueue

◆ swap