Type-erased single-instance byte storage. More...

#include <typed_buffer.hpp>

Public Types
using	allocator_type = Allocator
using	size_type = size_t
using	TypeIndex = utils::TypeIndex
using	StorageType = std::vector<std::byte, allocator_type>

Public Member Functions
constexpr	TypedBuffer () noexcept(std::is_nothrow_default_constructible_v< StorageType >)=default
	Default constructor. Creates an empty buffer with no associated type.
constexpr	TypedBuffer (const allocator_type &alloc) noexcept(std::is_nothrow_constructible_v< StorageType, const allocator_type & >)
	Constructs an empty buffer with a custom allocator.
constexpr	TypedBuffer (std::pmr::memory_resource resource) noexcept(std::is_nothrow_constructible_v< allocator_type, std::pmr::memory_resource >)
	Constructs an empty buffer from a PMR memory resource.
	TypedBuffer (std::nullptr_t)=delete
template<TypedBufferStorable T, typename... Args> requires std::constructible_from<T, Args...>
constexpr	TypedBuffer (std::in_place_type_t< T > tag, Args &&... args)
	Constructs a buffer holding a value of type T.
template<TypedBufferStorable T, typename... Args> requires std::constructible_from<T, Args...>
constexpr	TypedBuffer (std::in_place_type_t< T > tag, const allocator_type &alloc, Args &&... args)
	Constructs a buffer holding a value of type T with a custom allocator.
constexpr	TypedBuffer (const TypedBuffer &other)
constexpr	TypedBuffer (TypedBuffer &&other) noexcept(std::is_nothrow_move_constructible_v< StorageType >)
constexpr	~TypedBuffer () noexcept
constexpr TypedBuffer &	operator= (const TypedBuffer &other)
constexpr TypedBuffer &	operator= (TypedBuffer &&other) noexcept(std::is_nothrow_move_assignable_v< StorageType >)
template<TypedBufferStorable T>
constexpr void	ChangeType () noexcept
	Changes the stored type, destroying the current value if any.
constexpr void	Reset () noexcept
	Destroys the stored value and resets type information.
template<TypedBufferStorable T, typename... Args> requires std::constructible_from<T, Args...>
T &	Set (Args &&... args)
	Constructs (or replaces) the stored value in-place.
constexpr void	Swap (TypedBuffer &other) noexcept(std::is_nothrow_swappable_v< StorageType >)
	Swaps contents with another TypedBuffer.
constexpr bool	Empty () const noexcept
	Returns true if no value is currently stored.
constexpr bool	HasType () const noexcept
	Returns true if a type has been associated with this buffer.
template<TypedBufferStorable T>
constexpr bool	IsType () const noexcept
	Checks if the stored type matches T.
constexpr TypeIndex	StoredTypeId () const noexcept
	Gets the current stored type index.
constexpr size_type	ElementSize () const noexcept
	Returns the size in bytes of the stored element type, or 0 if no type is set.
template<TypedBufferStorable T>
T &	Value () noexcept
	Accesses the stored value.
template<TypedBufferStorable T>
const T &	Value () const noexcept
	Accesses the stored value (const).
constexpr auto	Bytes () const noexcept -> std::span< const std::byte >
	Returns a const byte span of the stored value (empty if no value is stored).

Static Public Member Functions
template<TypedBufferStorable T>
static consteval TypeIndex	TypeIndexOf () noexcept
	Gets the compile-time type index for T.

Friends
constexpr void	swap (TypedBuffer &lhs, TypedBuffer &rhs) noexcept(std::is_nothrow_swappable_v< StorageType >)

Detailed Description

template<typename Allocator = std::allocator<std::byte>>
class helios::container::TypedBuffer< Allocator >

Type-erased single-instance byte storage.

Stores exactly one instance of any TypedBufferStorable type in a std::vector<std::byte> backing buffer. The stored type is not fixed at class instantiation; it is set at runtime and verified on every access. Object lifetime is properly managed. Trivially-copyable types are fast-pathed.

Template Parameters

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

Definition at line 30 of file typed_buffer.hpp.

Member Typedef Documentation

◆ allocator_type

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

using helios::container::TypedBuffer< Allocator >::allocator_type = Allocator

Definition at line 32 of file typed_buffer.hpp.

◆ size_type

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

using helios::container::TypedBuffer< Allocator >::size_type = size_t

Definition at line 33 of file typed_buffer.hpp.

◆ StorageType

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

using helios::container::TypedBuffer< Allocator >::StorageType = std::vector<std::byte, allocator_type>

Definition at line 36 of file typed_buffer.hpp.

◆ TypeIndex

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

using helios::container::TypedBuffer< Allocator >::TypeIndex = utils::TypeIndex

Definition at line 34 of file typed_buffer.hpp.

Constructor & Destructor Documentation

◆ TypedBuffer() [1/8]

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

helios::container::TypedBuffer< Allocator >::TypedBuffer ( ) const

constexprdefaultnoexcept

Default constructor. Creates an empty buffer with no associated type.

◆ TypedBuffer() [2/8]

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

helios::container::TypedBuffer< Allocator >::TypedBuffer ( const allocator_type & alloc )

inlineexplicitconstexprnoexcept

Constructs an empty buffer with a custom allocator.

Parameters

alloc Allocator instance to use

Definition at line 47 of file typed_buffer.hpp.

◆ TypedBuffer() [3/8]

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

helios::container::TypedBuffer< Allocator >::TypedBuffer ( std::pmr::memory_resource * resource )

inlineexplicitconstexprnoexcept

Constructs an empty buffer 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 57 of file typed_buffer.hpp.

◆ TypedBuffer() [4/8]

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

helios::container::TypedBuffer< Allocator >::TypedBuffer ( std::nullptr_t )

delete

◆ TypedBuffer() [5/8]

template<typename Allocator>
requires std::constructible_from<T, Args...>

template<TypedBufferStorable T, typename... Args>
requires std::constructible_from<T, Args...>

helios::container::TypedBuffer< Allocator >::TypedBuffer	(	std::in_place_type_t< T >	tag,
		Args &&...	args )

explicitconstexpr

Constructs a buffer holding a value of type T.

Template Parameters

T	The type to store
Args	Constructor argument types

Parameters

tag	In-place type construction tag (use std::in_place_type<T>)
args	Arguments forwarded to T's constructor

TypedBuffer buf(std::in_place_type<int>, 42);

helios::container::TypedBuffer::TypedBuffer

constexpr TypedBuffer() noexcept(std::is_nothrow_default_constructible_v< StorageType >)=default

Default constructor. Creates an empty buffer with no associated type.

Definition at line 251 of file typed_buffer.hpp.

◆ TypedBuffer() [6/8]

template<typename Allocator>
requires std::constructible_from<T, Args...>

template<TypedBufferStorable T, typename... Args>
requires std::constructible_from<T, Args...>

helios::container::TypedBuffer< Allocator >::TypedBuffer	(	std::in_place_type_t< T >	tag,
		const allocator_type &	alloc,
		Args &&...	args )

constexpr

Constructs a buffer holding a value of type T with a custom allocator.

Template Parameters

T	The type to store
Args	Constructor argument types

Parameters

tag	In-place type construction tag (use std::in_place_type<T>)
alloc	Allocator instance to use
args	Arguments forwarded to T's constructor

Definition at line 262 of file typed_buffer.hpp.

◆ TypedBuffer() [7/8]

template<typename Allocator>

helios::container::TypedBuffer< Allocator >::TypedBuffer ( const TypedBuffer< Allocator > & other )

constexpr

Definition at line 274 of file typed_buffer.hpp.

◆ TypedBuffer() [8/8]

template<typename Allocator>

helios::container::TypedBuffer< Allocator >::TypedBuffer ( TypedBuffer< Allocator > && other )

constexprnoexcept

Definition at line 299 of file typed_buffer.hpp.

◆ ~TypedBuffer()

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

helios::container::TypedBuffer< Allocator >::~TypedBuffer ( )

inlineconstexprnoexcept

Definition at line 96 of file typed_buffer.hpp.

Member Function Documentation

◆ Bytes()

template<typename Allocator>

auto helios::container::TypedBuffer< Allocator >::Bytes ( ) const -> std::span< const std::byte >

nodiscardconstexprnoexcept

Returns a const byte span of the stored value (empty if no value is stored).

Returns: Byte span of the stored value

Definition at line 418 of file typed_buffer.hpp.

◆ ChangeType()

template<typename Allocator>

template<TypedBufferStorable T>

void helios::container::TypedBuffer< Allocator >::ChangeType ( )

constexprnoexcept

Changes the stored type, destroying the current value if any.

After this call Empty() is true and IsType<T>() is true. The underlying memory is retained for reuse.

Template Parameters

T	The new type

Definition at line 362 of file typed_buffer.hpp.

◆ ElementSize()

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

size_type helios::container::TypedBuffer< Allocator >::ElementSize ( ) const

inlinenodiscardconstexprnoexcept

Returns the size in bytes of the stored element type, or 0 if no type is set.

Returns: Size of the stored type in bytes

Definition at line 190 of file typed_buffer.hpp.

◆ Empty()

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

bool helios::container::TypedBuffer< Allocator >::Empty ( ) const

inlinenodiscardconstexprnoexcept

Returns true if no value is currently stored.

Returns: True if empty, false if a value is stored

Definition at line 146 of file typed_buffer.hpp.

◆ HasType()

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

bool helios::container::TypedBuffer< Allocator >::HasType ( ) const

inlinenodiscardconstexprnoexcept

Returns true if a type has been associated with this buffer.

Returns: True if a type is set, false if no type information is present

Definition at line 152 of file typed_buffer.hpp.

◆ IsType()

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

template<TypedBufferStorable T>

bool helios::container::TypedBuffer< Allocator >::IsType ( ) const

inlinenodiscardconstexprnoexcept

Checks if the stored type matches T.

Template Parameters

T	The type to check against

Returns: true if types match or no type is set

Definition at line 162 of file typed_buffer.hpp.

◆ operator=() [1/2]

template<typename Allocator>

auto helios::container::TypedBuffer< Allocator >::operator= ( const TypedBuffer< Allocator > & other )

constexpr

Definition at line 309 of file typed_buffer.hpp.

◆ operator=() [2/2]

template<typename Allocator>

auto helios::container::TypedBuffer< Allocator >::operator= ( TypedBuffer< Allocator > && other )

constexprnoexcept

Definition at line 344 of file typed_buffer.hpp.

◆ Reset()

template<typename Allocator>

void helios::container::TypedBuffer< Allocator >::Reset ( )

constexprnoexcept

Destroys the stored value and resets type information.

After this call both Empty() and !HasType() are true.

Definition at line 368 of file typed_buffer.hpp.

◆ Set()

template<typename Allocator>
requires std::constructible_from<T, Args...>

template<TypedBufferStorable T, typename... Args>
requires std::constructible_from<T, Args...>

T & helios::container::TypedBuffer< Allocator >::Set ( Args &&... args )

inline

Constructs (or replaces) the stored value in-place.

If a value of a different type is already stored it is destroyed first. The type is updated to T before construction.

Template Parameters

T	The type to store
Args	Constructor argument types

Parameters

args	Arguments forwarded to T's constructor

Returns: Reference to the newly constructed value

Definition at line 377 of file typed_buffer.hpp.

◆ StoredTypeId()

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

TypeIndex helios::container::TypedBuffer< Allocator >::StoredTypeId ( ) const

inlinenodiscardconstexprnoexcept

Gets the current stored type index.

Returns: Type index of the stored type, or an invalid index if no type is set

Definition at line 181 of file typed_buffer.hpp.

◆ Swap()

template<typename Allocator>

void helios::container::TypedBuffer< Allocator >::Swap ( TypedBuffer< Allocator > & other )

constexprnoexcept

Swaps contents with another TypedBuffer.

Parameters

other Buffer to swap with

Definition at line 392 of file typed_buffer.hpp.

◆ TypeIndexOf()

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

template<TypedBufferStorable T>

consteval TypeIndex helios::container::TypedBuffer< Allocator >::TypeIndexOf ( )

inlinestaticnodiscardconstevalnoexcept

Gets the compile-time type index for T.

Template Parameters

T	The type to get index for

Returns: Type index

Definition at line 172 of file typed_buffer.hpp.

◆ Value() [1/2]

template<typename Allocator>

template<TypedBufferStorable T>

const T & helios::container::TypedBuffer< Allocator >::Value ( ) const

inlinenodiscardnoexcept

Accesses the stored value (const).

Warning: Triggers assertion if the buffer is empty or the stored type doesn't match T.

Template Parameters

T	The expected type

Returns: Const reference to the stored value

Definition at line 410 of file typed_buffer.hpp.

◆ Value() [2/2]

template<typename Allocator>

template<TypedBufferStorable T>

T & helios::container::TypedBuffer< Allocator >::Value ( )

inlinenodiscardnoexcept

Accesses the stored value.

Warning: Triggers assertion if the buffer is empty or the stored type doesn't match T.

Template Parameters

T	The expected type

Returns: Reference to the stored value

Definition at line 401 of file typed_buffer.hpp.

◆ swap

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

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

friend

Definition at line 137 of file typed_buffer.hpp.

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ allocator_type

◆ size_type

◆ StorageType

◆ TypeIndex

Constructor & Destructor Documentation

◆ TypedBuffer() [1/8]

◆ TypedBuffer() [2/8]

◆ TypedBuffer() [3/8]

◆ TypedBuffer() [4/8]

◆ TypedBuffer() [5/8]

◆ TypedBuffer() [6/8]

◆ TypedBuffer() [7/8]

◆ TypedBuffer() [8/8]

◆ ~TypedBuffer()

Member Function Documentation

◆ Bytes()

◆ ChangeType()

◆ ElementSize()

◆ Empty()

◆ HasType()

◆ IsType()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Reset()

◆ Set()

◆ StoredTypeId()

◆ Swap()

◆ TypeIndexOf()

◆ Value() [1/2]

◆ Value() [2/2]

Friends And Related Symbol Documentation

◆ swap