RAII wrapper around file_handle. More...

#include <asioext/unique_file_handle.hpp>

Public Types
typedef unique_file_handle	lowest_layer_type
	A unique_file_handle is always the lowest layer. More...

Public Member Functions
	unique_file_handle () noexcept
	Construct an empy unique_file_handle. More...

	~unique_file_handle ()

	unique_file_handle (file_handle handle) noexcept
	Construct a unique_file_handle using a file_handle object. More...

	unique_file_handle (const file_handle::native_handle_type &handle) noexcept
	Construct a unique_file_handle using a native handle object. More...

	unique_file_handle (unique_file_handle &&other) noexcept
	Move-construct a unique_file_handle from another. More...

unique_file_handle &	operator= (unique_file_handle &&other)
	Move-assign a unique_file_handle from another. More...

lowest_layer_type &	lowest_layer () noexcept
	Get a reference to the lowest layer. More...

const lowest_layer_type &	lowest_layer () const noexcept
	Get a const reference to the lowest layer. More...

file_handle	get () noexcept
	Get the managed file_handle. More...

bool	is_open () const noexcept
	Determine whether the handle is open. More...

void	close ()
	Close the handle. More...

void	close (error_code &ec) noexcept
	Close the handle. More...

file_handle	release () noexcept
	Take ownership of the contained file_handle. More...

void	reset (file_handle handle)
	Replace the managed file_handle. More...

void	reset (file_handle handle, error_code &ec) noexcept
	Replace the managed file_handle. More...

Positioning functions
uint64_t	position ()
	Get the current file position. More...

uint64_t	position (error_code &ec) noexcept
	Get the current file position. More...

uint64_t	seek (seek_origin origin, int64_t offset)
	Change the read/write position. More...

uint64_t	seek (seek_origin origin, int64_t offset, error_code &ec) noexcept
	Change the read/write position. More...

Metadata functions
uint64_t	size ()
	Get the size of a file. More...

uint64_t	size (error_code &ec) noexcept
	Get the size of a file. More...

void	size (uint64_t new_size)
	Set the size of a file. More...

void	size (uint64_t new_size, error_code &ec) noexcept
	Set the size of a file. More...

file_perms	permissions ()
	Get the file's current access permissions. More...

file_perms	permissions (error_code &ec) noexcept
	Get the file's current access permissions. More...

void	permissions (file_perms perms, file_perm_options opts=file_perm_options::replace)
	Change file access permissions. More...

void	permissions (file_perms perms, error_code &ec) noexcept
	Change file access permissions. More...

void	permissions (file_perms perms, file_perm_options opts, error_code &ec) noexcept
	Change file access permissions. More...

file_attrs	attributes ()
	Get the file's attributes. More...

file_attrs	attributes (error_code &ec) noexcept
	Get the file's attributes. More...

void	attributes (file_attrs attrs, file_attr_options opts=file_attr_options::replace)
	Change the file's attributes. More...

void	attributes (file_attrs attrs, file_attr_options opts, error_code &ec) noexcept
	Change the file's attributes. More...

void	attributes (file_attrs attrs, error_code &ec) noexcept
	Change the file's attributes. More...

file_times	times ()
	Get the file's time data. More...

file_times	times (error_code &ec) noexcept
	Get the file's time data. More...

void	times (const file_times &new_times)
	Change a file's time data. More...

void	times (const file_times &new_times, error_code &ec) noexcept
	Change a file's time data. More...

SyncReadStream functions
template<typename MutableBufferSequence >
std::size_t	read_some (const MutableBufferSequence &buffers)
	Read some data from the file. More...

template<typename MutableBufferSequence >
std::size_t	read_some (const MutableBufferSequence &buffers, error_code &ec) noexcept
	Read some data from the file. More...

SyncWriteStream functions
template<typename ConstBufferSequence >
std::size_t	write_some (const ConstBufferSequence &buffers)
	Write some data to the file. More...

template<typename ConstBufferSequence >
std::size_t	write_some (const ConstBufferSequence &buffers, error_code &ec) noexcept
	Write some data to the file. More...

SyncRandomAccessReadDevice functions
template<typename MutableBufferSequence >
std::size_t	read_some_at (uint64_t offset, const MutableBufferSequence &buffers)
	Read some data from the file at the specified offset. More...

template<typename MutableBufferSequence >
std::size_t	read_some_at (uint64_t offset, const MutableBufferSequence &buffers, error_code &ec) noexcept
	Read some data from the file at the specified offset. More...

SyncRandomAccessWriteDevice functions
template<typename ConstBufferSequence >
std::size_t	write_some_at (uint64_t offset, const ConstBufferSequence &buffers)
	Write some data to the file at the specified offset. More...

template<typename ConstBufferSequence >
std::size_t	write_some_at (uint64_t offset, const ConstBufferSequence &buffers, error_code &ec) noexcept
	Write some data to the file at the specified offset. More...

Detailed Description

RAII wrapper around file_handle.

The unique_file_handle class provides a std::unique_ptr<>-like wrapper around a file_handle. The unique_file_handle owns the contained native handle.

unique_file_handle objects cannot be copied, but are move-constructible/ move-assignable if a compiler with C++11 support is used.

unique_file_handle models the following asio concepts:

SyncRandomAccessReadDevice
SyncRandomAccessWriteDevice
SyncReadStream
SyncWriteStream

Thread Safety:: Distinct objects: Safe.
Shared objects: Unsafe.

Note: If copying a handle (which is a costly operation) is really necessary, the asioext::duplicate() function can be used.

Example: asioext::unique_file_handle file = asioext::open(
"myfile.txt", asioext::open_flags::access_read_write |
asioext::open_flags::create_always);
// Write a string
const std::string content = "Hello world";
asio::write(file, asio::buffer(content));
// Read it back
// Note that we could avoid seek() by using write_at/read_t!
file.seek(asioext::seek_origin::from_begin, 0);
std::string content_returned(content.size());
asio::read(file, asio::buffer(content));

Member Typedef Documentation

◆ lowest_layer_type

typedef unique_file_handle asioext::unique_file_handle::lowest_layer_type

A unique_file_handle is always the lowest layer.

Constructor & Destructor Documentation

◆ unique_file_handle() [1/4]

asioext::unique_file_handle::unique_file_handle ( )

noexcept

Construct an empy unique_file_handle.

This constructor initializes the unique_file_handle to an empty state.

◆ ~unique_file_handle()

asioext::unique_file_handle::~unique_file_handle ( )

Destroy a unique_file_handle.

This destructor attempts to close the currently owned file handle. Failures are silently ignored.

◆ unique_file_handle() [2/4]

asioext::unique_file_handle::unique_file_handle ( file_handle handle )

explicitnoexcept

Construct a unique_file_handle using a file_handle object.

This constructor takes ownership of the given file_handle.

Parameters

handle The file_handle object which shall be assigned to this unique_file_handle object.

◆ unique_file_handle() [3/4]

asioext::unique_file_handle::unique_file_handle ( const file_handle::native_handle_type & handle )

explicitnoexcept

Construct a unique_file_handle using a native handle object.

This constructor takes ownership of the given native handle.

Parameters

handle The native handle object which shall be assigned to this unique_file_handle object.

◆ unique_file_handle() [4/4]

asioext::unique_file_handle::unique_file_handle ( unique_file_handle && other )

noexcept

Move-construct a unique_file_handle from another.

This constructor moves a handle from one object to another.

Parameters

other The other unique_file_handle object from which the move will occur.

Note: Following the move, the moved-from object is in the same state as if constructed using the unique_file_handle() constructor.

Member Function Documentation

◆ attributes() [1/5]

file_attrs asioext::unique_file_handle::attributes ( )

inline

Get the file's attributes.

This function returns the file's attributes as a file_attrs bitmask.

Returns: The file's attributes.

Exceptions

asio::system_error Thrown on failure.

◆ attributes() [2/5]

file_attrs asioext::unique_file_handle::attributes ( error_code & ec )

inlinenoexcept

Get the file's attributes.

This function returns the file's attributes as a file_attrs bitmask.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The file's attributes.

◆ attributes() [3/5]

void asioext::unique_file_handle::attributes	(	file_attrs	attrs,
		file_attr_options	opts = `file_attr_options::replace`
	)

inline

Change the file's attributes.

This function changes the file's attributes. Depending on whether file_attr_options::add_attrs, file_attr_options::remove_attrs are set, attributes are either added, removed or replaced.

Parameters

attrs	Attributes to set, add or remove.
opts	Options controlling this function's behavior.

Exceptions

asio::system_error Thrown on failure.

◆ attributes() [4/5]

void asioext::unique_file_handle::attributes	(	file_attrs	attrs,
		file_attr_options	opts,
		error_code &	ec
	)

inlinenoexcept

Change the file's attributes.

This function changes the file's attributes. Depending on whether file_attr_options::add_attrs, file_attr_options::remove_attrs are set, attributes are either added, removed or replaced.

Parameters

attrs	Attributes to set, add or remove.
opts	Options controlling this function's behavior.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ attributes() [5/5]

void asioext::unique_file_handle::attributes	(	file_attrs	attrs,
		error_code &	ec
	)

inlinenoexcept

Change the file's attributes.

This function changes the file's attributes. Depending on whether file_attr_options::add_attrs, file_attr_options::remove_attrs are set, attributes are either added, removed or replaced.

Parameters

attrs	Attributes to set, add or remove.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ close() [1/2]

void asioext::unique_file_handle::close ( )

inline

Close the handle.

This function closes the contained handle. Does nothing if the object contains no handle.

Exceptions

asio::system_error Thrown on failure.

◆ close() [2/2]

void asioext::unique_file_handle::close ( error_code & ec )

inlinenoexcept

Close the handle.

This function closes the contained handle. Does nothing if the object contains no handle.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ get()

file_handle asioext::unique_file_handle::get ( )

inlinenoexcept

Get the managed file_handle.

This function returns a copy of the managed file_handle.

Returns: A copy of the contained file_handle object. Ownership is not transferred to the caller.

◆ is_open()

bool asioext::unique_file_handle::is_open ( ) const

inlinenoexcept

Determine whether the handle is open.

◆ lowest_layer() [1/2]

lowest_layer_type& asioext::unique_file_handle::lowest_layer ( )

inlinenoexcept

Get a reference to the lowest layer.

This function returns a reference to the lowest layer in a stack of layers. Since a unique_file_handle cannot contain any further layers, it simply returns a reference to itself.

Returns: A reference to the lowest layer in the stack of layers. Ownership is not transferred to the caller.

◆ lowest_layer() [2/2]

const lowest_layer_type& asioext::unique_file_handle::lowest_layer ( ) const

inlinenoexcept

Get a const reference to the lowest layer.

This function returns a const reference to the lowest layer in a stack of layers. Since a unique_file_handle cannot contain any further layers, it simply returns a reference to itself.

Returns: A const reference to the lowest layer in the stack of layers. Ownership is not transferred to the caller.

◆ operator=()

unique_file_handle& asioext::unique_file_handle::operator= ( unique_file_handle && other )

Move-assign a unique_file_handle from another.

This assignment operator moves a handle from one object to another. If this object already owns a file handle, the current handle will be closed. This operation is potentially throwing.

Parameters

other The other unique_file_handle object from which the move will occur.

Note: Following the move, the moved-from object is in the same state as if constructed using the unique_file_handle() constructor.

◆ permissions() [1/5]

file_perms asioext::unique_file_handle::permissions ( )

inline

Get the file's current access permissions.

This function returns the file's current access permissions as a file_perms bitmask.

Returns: The file's access permissions.

Exceptions

asio::system_error Thrown on failure.

◆ permissions() [2/5]

file_perms asioext::unique_file_handle::permissions ( error_code & ec )

inlinenoexcept

Get the file's current access permissions.

This function returns the file's current access permissions as a file_perms bitmask.

Returns: The file's access permissions.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ permissions() [3/5]

void asioext::unique_file_handle::permissions	(	file_perms	perms,
		file_perm_options	opts = `file_perm_options::replace`
	)

inline

Change file access permissions.

This function changes the file's access permissions. Depending on whether file_perm_options::add_perms, file_perm_options::remove_perms are set, permissions are either added, removed or replaced.

Parameters

perms	Permissions to set, add or remove.
opts	Options controlling this function's behavior.

Exceptions

asio::system_error Thrown on failure.

◆ permissions() [4/5]

void asioext::unique_file_handle::permissions	(	file_perms	perms,
		error_code &	ec
	)

inlinenoexcept

Change file access permissions.

This function changes the file's access permissions. Depending on whether file_perm_options::add_perms, file_perm_options::remove_perms are set, permissions are either added, removed or replaced.

Parameters

perms	Permissions to set, add or remove.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ permissions() [5/5]

void asioext::unique_file_handle::permissions	(	file_perms	perms,
		file_perm_options	opts,
		error_code &	ec
	)

inlinenoexcept

Change file access permissions.

This function changes the file's access permissions. Depending on whether file_perm_options::add_perms, file_perm_options::remove_perms are set, permissions are either added, removed or replaced.

Parameters

perms	Permissions to set, add or remove.
opts	Options controlling this function's behavior.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ position() [1/2]

uint64_t asioext::unique_file_handle::position ( )

inline

Get the current file position.

This function retrieves the current read/write position of this file handle, relative to the file's beginning.

Returns: The current absolute file position.

Exceptions

asio::system_error Thrown on failure.

◆ position() [2/2]

uint64_t asioext::unique_file_handle::position ( error_code & ec )

inlinenoexcept

Get the current file position.

This function retrieves the current read/write position of this file handle, relative to the file's beginning.

Returns: The current absolute file position.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ read_some() [1/2]

template<typename MutableBufferSequence >

std::size_t asioext::unique_file_handle::read_some ( const MutableBufferSequence & buffers )

inline

Read some data from the file.

This function is used to read data from the file, starting at the file_handle's current file position. The function call will block until one or more bytes of data has been read successfully, or until an error occurs.

Parameters

buffers One or more buffers into which the data will be read.

Returns: The number of bytes read.

Exceptions

asio::system_error Thrown on failure. An error code of asio::error::eof indicates that the end of file was reached.

Note: The read_some operation may not read all of the requested number of bytes. Consider using the asio::read function if you need to ensure that the requested amount of data is read before the blocking operation completes.

Example: To read into a single data buffer use the asio::buffer function as follows:
fh.read_some(asio::buffer(data, size));
See the asio::buffer documentation for information on reading into multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

◆ read_some() [2/2]

template<typename MutableBufferSequence >

std::size_t asioext::unique_file_handle::read_some	(	const MutableBufferSequence &	buffers,
		error_code &	ec
	)

inlinenoexcept

Read some data from the file.

This function is used to read data from the file, starting at the file_handle's current file position. The function call will block until one or more bytes of data has been read successfully, or until an error occurs.

Parameters

buffers	One or more buffers into which the data will be read.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The number of bytes read. Returns 0 if an error occurred.

Note: The read_some operation may not read all of the requested number of bytes. Consider using the asio::read function if you need to ensure that the requested amount of data is read before the blocking operation completes.

◆ read_some_at() [1/2]

template<typename MutableBufferSequence >

std::size_t asioext::unique_file_handle::read_some_at	(	uint64_t	offset,
		const MutableBufferSequence &	buffers
	)

inline

Read some data from the file at the specified offset.

This function is used to read data from the file. The function call will block until one or more bytes of data has been read successfully, or until an error occurs.

Parameters

offset	The offset at which the data will be read, relative to the file's beginning.
buffers	One or more buffers into which the data will be read.

Returns: The number of bytes read.

Exceptions

asio::system_error Thrown on failure. An error code of asio::error::eof indicates that the end of the file was reached.

Note: The read_some operation may not read all of the requested number of bytes. Consider using the asio::read_at function if you need to ensure that the requested amount of data is read before the blocking operation completes.

Example: To read into a single data buffer use the asio::buffer function as follows:
handle.read_some_at(42, asio::buffer(data, size));
See the asio::buffer documentation for information on reading into multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

◆ read_some_at() [2/2]

template<typename MutableBufferSequence >

std::size_t asioext::unique_file_handle::read_some_at	(	uint64_t	offset,
		const MutableBufferSequence &	buffers,
		error_code &	ec
	)

inlinenoexcept

Read some data from the file at the specified offset.

This function is used to read data from the file. The function call will block until one or more bytes of data has been read successfully, or until an error occurs.

Parameters

offset	The offset at which the data will be read, relative to the file's beginning.
buffers	One or more buffers into which the data will be read.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The number of bytes read. Returns 0 if an error occurred.

Note: The read_some operation may not read all of the requested number of bytes. Consider using the asio::read_at function if you need to ensure that the requested amount of data is read before the blocking operation completes.

◆ release()

file_handle asioext::unique_file_handle::release ( )

noexcept

Take ownership of the contained file_handle.

This function transfers ownership of the contained file_handle to the caller. The unique_file_handle object is reset to an empty state (i.e. no file opened).

Returns: The contained file_handle. The caller is now responsible to close it.

Warning: This function is dangerous. It is highly unlikely that you'll ever need to use this.

◆ reset() [1/2]

void asioext::unique_file_handle::reset ( file_handle handle )

Replace the managed file_handle.

This function closes the currently managed handle (if any), and replaces it with the given one.

Parameters

handle The new file_handle to manage. Ownership is transferred to the unique_file_handle.

Exceptions

asio::system_error Thrown on failure.

◆ reset() [2/2]

void asioext::unique_file_handle::reset	(	file_handle	handle,
		error_code &	ec
	)

noexcept

Replace the managed file_handle.

This function closes the currently managed handle (if any), and replaces it with the given one.

Parameters

handle	The new file_handle to manage. Ownership is transferred to the unique_file_handle.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ seek() [1/2]

uint64_t asioext::unique_file_handle::seek	(	seek_origin	origin,
		int64_t	offset
	)

inline

Change the read/write position.

This function repositions the current read/write position of this file_handle by offset, relative to the origin specified by origin.

Parameters

origin	The origin of `offset`.
offset	The offset by which the current position's modified.

Returns: The new absolute file position.

Exceptions

asio::system_error Thrown on failure.

◆ seek() [2/2]

uint64_t asioext::unique_file_handle::seek	(	seek_origin	origin,
		int64_t	offset,
		error_code &	ec
	)

inlinenoexcept

Change the read/write position.

This function repositions the current read/write position of this file_handle by offset, relative to the origin specified by origin.

Parameters

origin	The origin of `offset`.
offset	The offset by which the current position's modified.

Returns: The new absolute file position.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ size() [1/4]

uint64_t asioext::unique_file_handle::size ( )

inline

Get the size of a file.

This function retrieves the size of a file, in bytes.

Returns: The total number of bytes in this file.

Exceptions

asio::system_error Thrown on failure.

◆ size() [2/4]

uint64_t asioext::unique_file_handle::size ( error_code & ec )

inlinenoexcept

Get the size of a file.

This function retrieves the size of a file, in bytes.

Returns: The total number of bytes in this file.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ size() [3/4]

void asioext::unique_file_handle::size ( uint64_t new_size )

inline

Set the size of a file.

This function resizes the file so its new size matches new_size.

Parameters

new_size The new total size of the file (in bytes).

Exceptions

asio::system_error Thrown on failure.

◆ size() [4/4]

void asioext::unique_file_handle::size	(	uint64_t	new_size,
		error_code &	ec
	)

inlinenoexcept

Set the size of a file.

This function resizes the file so its new size matches new_size.

Parameters

new_size	The new total size of the file (in bytes).
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ times() [1/4]

file_times asioext::unique_file_handle::times ( )

inline

Get the file's time data.

This function retrieves the various times associated with a file and copies them into a file_times structure.

Times in the file_times struct that are not available for this file are zero-initialized.

Returns: The file's time data.

Exceptions

asio::system_error Thrown on failure.

◆ times() [2/4]

file_times asioext::unique_file_handle::times ( error_code & ec )

inlinenoexcept

Get the file's time data.

This function retrieves the various times associated with a file and copies them into a file_times structure.

Times in the file_times struct that are not available for this file are zero-initialized.

Parameters

ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The file's time data.

◆ times() [3/4]

void asioext::unique_file_handle::times ( const file_times & new_times )

inline

Change a file's time data.

This function replaces a file's time data with the given values. File times that are set to zero inside the file_times structure remain unchanged.

Parameters

new_times The new file times. Zero values are ignored.

Exceptions

asio::system_error Thrown on failure.

◆ times() [4/4]

void asioext::unique_file_handle::times	(	const file_times &	new_times,
		error_code &	ec
	)

inlinenoexcept

Change a file's time data.

This function replaces a file's time data with the given values. File times that are set to zero inside the file_times structure remain unchanged.

Parameters

new_times	The new file times. Zero values are ignored.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

◆ write_some() [1/2]

template<typename ConstBufferSequence >

std::size_t asioext::unique_file_handle::write_some ( const ConstBufferSequence & buffers )

inline

Write some data to the file.

This function is used to write data to the file, starting at the file_handle's current file position. The function call will block until one or more bytes of the data has been written successfully, or until an error occurs.

Parameters

buffers One or more data buffers to be written to the file.

Returns: The number of bytes written.

Exceptions

asio::system_error Thrown on failure.

Note: The write_some operation may not transmit all of the data to the peer. Consider using the asio::write function if you need to ensure that all data is written before the blocking operation completes.

Example: To write a single data buffer use the asio::buffer function as follows:
fh.write_some(asio::buffer(data, size));
See the asio::buffer documentation for information on writing multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

◆ write_some() [2/2]

template<typename ConstBufferSequence >

std::size_t asioext::unique_file_handle::write_some	(	const ConstBufferSequence &	buffers,
		error_code &	ec
	)

inlinenoexcept

Write some data to the file.

This function is used to write data to the file, starting at the file_handle's current file position. The function call will block until one or more bytes of the data has been written successfully, or until an error occurs.

Parameters

buffers	One or more data buffers to be written to the file.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The number of bytes written. Returns 0 if an error occurred.

Note: The write_some operation may not transmit all of the data to the peer. Consider using the asio::write function if you need to ensure that all data is written before the blocking operation completes.

◆ write_some_at() [1/2]

template<typename ConstBufferSequence >

std::size_t asioext::unique_file_handle::write_some_at	(	uint64_t	offset,
		const ConstBufferSequence &	buffers
	)

inline

Write some data to the file at the specified offset.

This function is used to write data to the file. The function call will block until one or more bytes of the data has been written successfully, or until an error occurs.

Parameters

offset	The offset at which the data will be written, relative to the file's beginning.
buffers	One or more data buffers to be written.

Returns: The number of bytes written.

Exceptions

asio::system_error Thrown on failure.

Note: The write_some_at operation may not write all of the data. Consider using the asio::write_at function if you need to ensure that all data is written before the blocking operation completes.

Example: To write a single data buffer use the asio::buffer function as follows:
fh.write_some_at(42, asio::buffer(data, size));
See the asio::buffer documentation for information on writing multiple buffers in one go, and how to use it with arrays, boost::array or std::vector.

◆ write_some_at() [2/2]

template<typename ConstBufferSequence >

std::size_t asioext::unique_file_handle::write_some_at	(	uint64_t	offset,
		const ConstBufferSequence &	buffers,
		error_code &	ec
	)

inlinenoexcept

Write some data to the file at the specified offset.

This function is used to write data to the file. The function call will block until one or more bytes of the data has been written successfully, or until an error occurs.

Parameters

offset	The offset at which the data will be written, relative to the file's beginning.
buffers	One or more data buffers to be written to the handle.
ec	Set to indicate what error occurred. If no error occurred, the object is reset.

Returns: The number of bytes written. Returns 0 if an error occurred.

Note: The write_some_at operation may not write all of the data. Consider using the asio::write_at function if you need to ensure that all data is written before the blocking operation completes.

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ lowest_layer_type

Constructor & Destructor Documentation

◆ unique_file_handle() [1/4]

◆ ~unique_file_handle()

◆ unique_file_handle() [2/4]

◆ unique_file_handle() [3/4]

◆ unique_file_handle() [4/4]

Member Function Documentation

◆ attributes() [1/5]

◆ attributes() [2/5]

◆ attributes() [3/5]

◆ attributes() [4/5]

◆ attributes() [5/5]

◆ close() [1/2]

◆ close() [2/2]

◆ get()

◆ is_open()

◆ lowest_layer() [1/2]

◆ lowest_layer() [2/2]

◆ operator=()

◆ permissions() [1/5]

◆ permissions() [2/5]

◆ permissions() [3/5]

◆ permissions() [4/5]

◆ permissions() [5/5]

◆ position() [1/2]

◆ position() [2/2]

◆ read_some() [1/2]

◆ read_some() [2/2]

◆ read_some_at() [1/2]

◆ read_some_at() [2/2]

◆ release()

◆ reset() [1/2]

◆ reset() [2/2]

◆ seek() [1/2]

◆ seek() [2/2]

◆ size() [1/4]

◆ size() [2/4]

◆ size() [3/4]

◆ size() [4/4]

◆ times() [1/4]

◆ times() [2/4]

◆ times() [3/4]

◆ times() [4/4]

◆ write_some() [1/2]

◆ write_some() [2/2]

◆ write_some_at() [1/2]

◆ write_some_at() [2/2]