Overview

Represents a read-only view of a contiguous block of bytes.

ConstBuf is intended for passing ownership of read-only data, or providing an unowned view, optionally slicing the view between layers. Unlike Buf, ConstBuf does not support Reclaim() or expose its base pointer. Once a ConstBuf is sliced or truncated, the excluded bytes cannot be recovered.

An empty() ConstBuf has no bytes (size() == 0). A null ConstBuf has no bytes, and its data() pointer is nullptr. A ConstBuf is null when default-constructed, moved-from, or reset.

An empty ConstBuf is not necessarily null (for example, if it was created with ConstBuf::ZeroLength() or sliced or truncated to length 0), in which case data() returns a non-null pointer.

Nullness can be checked via comparison to nullptr (buf == nullptr, buf != nullptr). operator bool is not provided to prevent confusion between nullness and emptiness.

Public Types
using	value_type = std::byte

using	size_type = size_t

using	difference_type = ptrdiff_t

using	pointer = const std::byte *

using	reference = const std::byte &

using	iterator = Buf::const_iterator

using	const_pointer = const std::byte *

using	const_reference = const std::byte &

using	const_iterator = Buf::const_iterator

Public Member Functions
constexpr	ConstBuf ()=default
	Constructs a null `ConstBuf`.

constexpr	ConstBuf (std::nullptr_t) noexcept
	Constructs a null `ConstBuf`.

template<typename T , typename = std::enable_if_t<std::is_integral_v<T>>>
	ConstBuf (T)=delete

constexpr	ConstBuf (ConstBuf &&other) noexcept

constexpr	ConstBuf (Buf &&other) noexcept

	ConstBuf (const ConstBuf &)=delete

	~ConstBuf ()=default
	Destructor. Releases the owned memory (if any) back to the allocator.

ConstBuf &	operator= (ConstBuf &&other) noexcept=default

ConstBuf &	operator= (Buf &&other) noexcept

ConstBuf &	operator= (const ConstBuf &)=delete

ConstBuf &	operator= (std::nullptr_t) noexcept

template<typename T , typename = std::enable_if_t<std::is_integral_v<T>>>
ConstBuf &	operator= (T)=delete
	Integers cannot be assigned to a `ConstBuf`, not even the literal `0`.

	operator bool () const =delete

reference	operator[] (size_t index) const
	Accesses the byte at the specified index.

constexpr pointer	data () const

constexpr size_t	size () const
	Returns the number of bytes in the buffer view.

constexpr bool	empty () const

iterator	begin () const
	Returns a read-only iterator pointing to the beginning of the data.

iterator	end () const
	Returns a read-only iterator pointing past the end of the data.

const_iterator	cbegin () const
	Returns a read-only iterator pointing to the beginning of the data.

const_iterator	cend () const
	Returns a read-only iterator pointing past the end of the data.

constexpr bool	owned () const

constexpr Deallocator *	deallocator () const

void	reset ()
	Frees the owned memory (if any) and sets the buffer to null.

void	swap (ConstBuf &other) noexcept
	Exchanges the contents of this `ConstBuf` with `other`.

Static Public Member Functions
static ConstBuf	ZeroLength () noexcept

static ConstBuf	Unowned (ConstByteSpan span)
	Creates an unowned `ConstBuf` from a `ConstByteSpan`.

static ConstBuf	Unowned (const std::byte *data, size_t size_bytes)
	Creates an unowned `ConstBuf` from a pointer and size in bytes.

Friends
class	multibuf::v2::internal::GenericMultiBuf

constexpr bool	operator== (const ConstBuf &lhs, std::nullptr_t) noexcept

constexpr bool	operator== (std::nullptr_t, const ConstBuf &rhs) noexcept

constexpr bool	operator!= (const ConstBuf &lhs, std::nullptr_t) noexcept

constexpr bool	operator!= (std::nullptr_t, const ConstBuf &rhs) noexcept

void	swap (ConstBuf &lhs, ConstBuf &rhs) noexcept
	Exchanges the contents of two `ConstBuf`s.

ConstBuf	Slice (ConstBuf &&const_buf, size_t offset, size_t length)

Constructor & Destructor Documentation

◆ ConstBuf() [1/3]

template<typename T , typename = std::enable_if_t<std::is_integral_v<T>>>

pw::ConstBuf::ConstBuf ( T )

delete

Integers do not convert to ConstBuf. Without this, the literal 0 would convert through the nullptr_t constructor, so passing 0 where a ConstBuf is expected would silently produce a null buffer.

◆ ConstBuf() [2/3]

constexpr pw::ConstBuf::ConstBuf ( ConstBuf && other )

inlineconstexprnoexcept

Move constructor.

The moved-from ConstBuf is left null.

◆ ConstBuf() [3/3]

constexpr pw::ConstBuf::ConstBuf ( Buf && other )

inlineconstexprnoexcept

Move-constructs a ConstBuf from a mutable Buf (move conversion).

The moved-from Buf is left null.

Member Function Documentation

◆ data()

constexpr pointer pw::ConstBuf::data ( ) const

inlineconstexpr

Returns a pointer to the read-only data, or nullptr if the ConstBuf is null.

Note: An empty ConstBuf that is not null (e.g. sliced or truncated to length 0) returns a non-null pointer. data() is only nullptr when the buffer is null.

◆ deallocator()

constexpr Deallocator * pw::ConstBuf::deallocator ( ) const

inlineconstexpr

Returns a pointer to the deallocator if this buffer owns the underlying memory allocation, or nullptr if the buffer is unowned or null.

◆ empty()

constexpr bool pw::ConstBuf::empty ( ) const

inlineconstexpr

Returns true if the buffer view is empty (has no bytes).

empty() returns true for both null buffers and non-null buffers of size zero (e.g. sliced or truncated to length 0).

◆ operator bool()

pw::ConstBuf::operator bool ( ) const

explicitdelete

operator bool is not provided to prevent confusion between nullness and emptiness. Use buf == nullptr to check for null, or buf.empty() for size 0.

◆ operator=() [1/3]

ConstBuf & pw::ConstBuf::operator= ( Buf && other )

inlinenoexcept

Move conversion assignment operator from Buf.

The moved-from Buf is left null.

◆ operator=() [2/3]

ConstBuf & pw::ConstBuf::operator= ( ConstBuf && other )

defaultnoexcept

Move assignment operator.

The moved-from ConstBuf is left null.

◆ operator=() [3/3]

ConstBuf & pw::ConstBuf::operator= ( std::nullptr_t )

inlinenoexcept

Frees the owned memory (if any) and sets the buffer to null. Same as reset().

◆ owned()

constexpr bool pw::ConstBuf::owned ( ) const

inlineconstexpr

Returns true if this buffer owns the underlying memory allocation (deallocator() != nullptr), or false if the buffer is unowned or null.

◆ ZeroLength()

static ConstBuf pw::ConstBuf::ZeroLength ( )

inlinestaticnoexcept

Returns an empty, non-null, unowned ConstBuf (empty() == true, buf != nullptr, owned() == false).

Friends And Related Function Documentation

◆ Slice

ConstBuf Slice	(	ConstBuf &&	const_buf,
		size_t	offset,
		size_t	length
	)

friend

Slices a read-only ConstBuf by shifting its start address and setting its size.

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

pw_buf/public/pw_buf/buf.h

Overview

Public Types

Public Member Functions

Static Public Member Functions

Friends

Constructor & Destructor Documentation

◆ ConstBuf() [1/3]

◆ ConstBuf() [2/3]

◆ ConstBuf() [3/3]

Member Function Documentation

◆ data()

◆ deallocator()

◆ empty()

◆ operator bool()

◆ operator=() [1/3]

◆ operator=() [2/3]

◆ operator=() [3/3]

◆ owned()

◆ ZeroLength()

Friends And Related Function Documentation

◆ Slice