Overview

Represents a mutable view of a contiguous block of bytes.

An empty() Buf has no bytes (size() == 0). A null Buf has no bytes, and its base() and data() are nullptr. A Buf is null when default-constructed, moved-from, reset, or when allocation fails.

An empty Buf is not necessarily null (for example, if it has been sliced or truncated to length 0), in which case base() and data() return non-null pointers.

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 = std::byte *

using	reference = std::byte &

using	const_pointer = const std::byte *

using	const_reference = const std::byte &

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

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

constexpr	Buf (Buf &&other) noexcept

	Buf (UniquePtr< std::byte[]> &&buffer)

	Buf (UniquePtr< std::byte[]> &&buffer, size_t offset)

	Buf (UniquePtr< std::byte[]> &&buffer, size_t offset, size_t size)
	Constructs an owned `Buf` from a `UniquePtr`, offset, and size.

constexpr	Buf (std::byte *allocation, size_t size, Deallocator &deallocator)
	Constructs an owned `Buf` from a raw buffer, size, and deallocator.

constexpr	Buf (std::byte *allocation, size_t offset, size_t size, Deallocator &deallocator)

	Buf (const Buf &)=delete

Buf &	operator= (Buf &&other) noexcept

Buf &	operator= (const Buf &)=delete

Buf &	operator= (std::nullptr_t) noexcept

	operator bool () const =delete

	operator const ConstBuf & () const &

	operator const ConstBuf && () const &&

const_reference	operator[] (size_t index) const
	Accesses the byte at the specified index as read-only.

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

constexpr const_pointer	data () const

constexpr pointer	data ()

constexpr size_t	size () const
	Returns the size of the buffer.

constexpr bool	empty () const

constexpr const std::byte *	base () const

constexpr Deallocator *	deallocator () const

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

const_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.

iterator	begin ()
	Returns a mutable iterator pointing to the beginning of the data.

iterator	end ()
	Returns a mutable iterator pointing past the end of the data.

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

Static Public Member Functions
static Buf	Unowned (ByteSpan span, size_t offset, size_t size)
	Creates an unowned `Buf` from a `ByteSpan`, offset, and size.

static Buf	Unowned (ByteSpan span, size_t offset=0)

static Buf	Unowned (std::byte *base, size_t offset, size_t size)
	Creates an unowned `Buf` from a pointer, offset, and size.

static Buf	Unowned (std::byte *base, size_t size)
	Creates an unowned `Buf` from a pointer and size.

static Buf	Allocate (Allocator &allocator, size_t size)

static Buf	Allocate (Allocator &allocator, size_t offset, size_t size)

static Buf	TryAllocate (Allocator &allocator, size_t size)

static Buf	TryAllocate (Allocator &allocator, size_t offset, size_t size)

Friends
class	ConstBuf

class	multibuf::v2::internal::GenericMultiBuf

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

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

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

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

Buf	Slice (Buf &&buf, size_t offset, size_t length)
	Slices a mutable `Buf` by shifting its start address and setting its size.

Buf	Reclaim (Buf &&buf, size_t prefix_count, size_t suffix_count)

Constructor & Destructor Documentation

◆ Buf() [1/3]

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

inlineconstexprnoexcept

Move constructor.

The moved-from Buf is left null.

◆ Buf() [2/3]

pw::Buf::Buf ( UniquePtr< std::byte[]> && buffer )

inlineexplicit

Constructs an owned Buf from a UniquePtr.

If buffer is empty/null, constructs a null Buf.

◆ Buf() [3/3]

constexpr pw::Buf::Buf	(	std::byte *	allocation,
		size_t	offset,
		size_t	size,
		Deallocator &	deallocator
	)

inlineexplicitconstexpr

Constructs an owned Buf from a raw buffer, offset, size, and deallocator.

Member Function Documentation

◆ Allocate() [1/2]

static Buf pw::Buf::Allocate	(	Allocator &	allocator,
		size_t	offset,
		size_t	size
	)

static

Allocates a new owned Buf of the specified allocation size, shifted to offset, with the specified size.

Asserts if allocation fails.

◆ Allocate() [2/2]

static Buf pw::Buf::Allocate	(	Allocator &	allocator,
		size_t	size
	)

inlinestatic

Allocates a new owned Buf of the specified size.

Asserts if allocation fails.

◆ base()

constexpr const std::byte * pw::Buf::base ( ) const

inlineconstexpr

Returns a pointer to the base address of the underlying memory buffer, or nullptr if the Buf is null.

Unlike data(), which points to the start of the current view, base() always points to the beginning of the underlying memory allocation or span from which this buffer was created.

◆ data() [1/2]

constexpr pointer pw::Buf::data ( )

inlineconstexpr

Returns a pointer to the mutable data, or nullptr if the Buf is null.

Note: An empty Buf 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.

◆ data() [2/2]

constexpr const_pointer pw::Buf::data ( ) const

inlineconstexpr

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

Note: An empty Buf 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::Buf::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::Buf::empty ( ) const

inlineconstexpr

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

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

◆ operator bool()

pw::Buf::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 const ConstBuf &()

pw::Buf::operator const ConstBuf & ( ) const &

inline

Implicit conversion to const ConstBuf& and const ConstBuf&&. Conversion to ConstBuf& is not supported, since truncating the ConstBuf& would nullify this Buf.

Note: Prefer accepting pw::ConstByteSpan (or pw::span<const std::byte>) by value instead of const ConstBuf& for functions that only require read-only access to the buffer's contents.

◆ operator=() [1/2]

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

inlinenoexcept

Move assignment operator.

The moved-from Buf is left null.

◆ operator=() [2/2]

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

inlinenoexcept

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

◆ TryAllocate() [1/2]

static Buf pw::Buf::TryAllocate	(	Allocator &	allocator,
		size_t	offset,
		size_t	size
	)

static

Allocates a new owned Buf of the specified allocation size, shifted to offset, with the specified size.

Returns a null Buf if allocation fails.

◆ TryAllocate() [2/2]

static Buf pw::Buf::TryAllocate	(	Allocator &	allocator,
		size_t	size
	)

inlinestatic

Allocates a new owned Buf of the specified size.

Returns a null Buf if allocation fails.

Friends And Related Function Documentation

◆ Reclaim

Buf Reclaim	(	Buf &&	buf,
		size_t	prefix_count,
		size_t	suffix_count
	)

friend

Reclaims up to prefix_count bytes at the beginning and suffix_count bytes at the end of the buffer.

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

◆ Buf() [1/3]

◆ Buf() [2/3]

◆ Buf() [3/3]

Member Function Documentation

◆ Allocate() [1/2]

◆ Allocate() [2/2]

◆ base()

◆ data() [1/2]

◆ data() [2/2]

◆ deallocator()

◆ empty()

◆ operator bool()

◆ operator const ConstBuf &()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ TryAllocate() [1/2]

◆ TryAllocate() [2/2]

Friends And Related Function Documentation

◆ Reclaim