asioext::open_flags

Specifies semantics for opening files. More...

Enumerations
enum	asioext::open_flags {   asioext::open_flags::none = 0, asioext::open_flags::access_read = 1 << 0, asioext::open_flags::access_write = 1 << 1, asioext::open_flags::access_read_write = access_read | access_write,   asioext::open_flags::create_new = 1 << 2, asioext::open_flags::create_always = 1 << 3, asioext::open_flags::open_existing = 1 << 4, asioext::open_flags::open_always = 1 << 5,   asioext::open_flags::truncate_existing = 1 << 6, asioext::open_flags::exclusive_read = 1 << 7, asioext::open_flags::exclusive_write = 1 << 8 }
	Specifies semantics for opening files. More...

Functions
bool	asioext::is_valid (open_flags flags) noexcept
	Check whether a set of open flags is valid. More...

Detailed Description

Specifies semantics for opening files.

Enumeration Type Documentation

open_flags

enum asioext::open_flags

strong

Specifies semantics for opening files.

This enum of bitmask values controls the behaviour of the asioext::open(). open_flags meets the requirements of BitmaskType.

open() converts these to their platform's native equivalent (if possible). Flags that are only available on certain platforms are marked as such.

There are 4 categories of flags:

• File access flags (access_read, ...)
• File creation disposition flags (create_new, ...)
• Sharing mode flags (exclusive_read, ...)
• Special flags (async, ...)

File creation disposition flags are mutually exclusive. Specifying more than one is an error.

Enumerator
none	No options are set.
access_read	Request read access to the file.
access_write	Request write access to the file.
access_read_write	Request read and write access to the file. Note that this is equivalent to: access_read | access_write
create_new	Attempt to create a new file. Fail if the file already exists.
create_always	Always create a new file. If the file already exists, it is truncated.
open_existing	Attempt to open an existing file. Fail if no such file exists.
open_always	Always open the file. If no such file exists, it is created.
truncate_existing	Attempt to open and truncate the file. Fail if no such file exists. This requires the access_write bit to be set.
exclusive_read	Request exclusive read access to the file. Note Currently only implemented on Windows.
exclusive_write	Request exclusive write access to the file. Note Currently only implemented on Windows.

Function Documentation

is_valid()

bool asioext::is_valid ( open_flags  flags )

noexcept

Check whether a set of open flags is valid.

This function checks whether the given flags are valid, i.e. no mutually exclusive or unsupported flags have been specified.