std:: basic_osyncstream
Defined in header
<syncstream>
|
||
template
<
class
CharT,
|
(since C++20) | |
The class template
std::basic_osyncstream
is a convenience wrapper for
std::basic_syncbuf
. It provides a mechanism to synchronize threads writing to the same stream.
It can be used with a named variable:
as well as with a temporary:
std::osyncstream(std::cout) << "Hello, " << "World!" << '\n';
It provides the guarantee that all output made to the same final destination buffer (
std::cout
in the examples above) will be free of data races and will not be interleaved or garbled in any way, as long as every write to that final destination buffer is made through (possibly different) instances of
std::basic_osyncstream
.
Typical implementation of
std::basic_osyncstream
holds only one member: the wrapped
std::basic_syncbuf
.
Inheritance diagram
Several typedefs for common character types are provided:
Defined in header
<syncstream>
|
|
Type | Definition |
std::osyncstream
|
std :: basic_osyncstream < char > |
std::wosyncstream
|
std :: basic_osyncstream < wchar_t > |
Member types
Member type | Definition |
char_type
|
CharT
|
traits_type
|
Traits
; the program is ill-formed if
Traits::char_type
is not
CharT
.
|
int_type
|
Traits::int_type
|
pos_type
|
Traits::pos_type
|
off_type
|
Traits::off_type
|
allocator_type
|
Allocator
|
streambuf_type
|
std:: basic_streambuf < CharT, Traits > |
syncbuf_type
|
std:: basic_syncbuf < CharT, Traits, Allocator > |
Member functions
constructs a
basic_osyncstream
object
(public member function) |
|
assigns a
basic_osyncstream
object
(public member function) |
|
destroys the
basic_osyncstream
and emits its internal buffer
(public member function) |
|
obtains a pointer to the underlying
basic_syncbuf
(public member function) |
|
obtains a pointer to the final destination stream buffer
(public member function) |
|
calls
emit()
on the underlying
basic_syncbuf
to transmit its internal data to the final destination
(public member function) |
Inherited from std:: basic_ostream
Member functions
Formatted output |
|
inserts formatted data
(public member function of
std::basic_ostream<CharT,Traits>
)
|
|
Unformatted output |
|
inserts a character
(public member function of
std::basic_ostream<CharT,Traits>
)
|
|
inserts blocks of characters
(public member function of
std::basic_ostream<CharT,Traits>
)
|
|
Positioning |
|
returns the output position indicator
(public member function of
std::basic_ostream<CharT,Traits>
)
|
|
sets the output position indicator
(public member function of
std::basic_ostream<CharT,Traits>
)
|
|
Miscellaneous |
|
synchronizes with the underlying storage device
(public member function of
std::basic_ostream<CharT,Traits>
)
|
Member classes
implements basic logic for preparation of the stream for output operations
(public member class of
std::basic_ostream<CharT,Traits>
)
|
Inherited from std:: basic_ios
Member types
Member type | Definition |
char_type
|
CharT
|
traits_type
|
Traits
|
int_type
|
Traits::int_type
|
pos_type
|
Traits::pos_type
|
off_type
|
Traits::off_type
|
Member functions
State functions |
|
checks if no error has occurred i.e. I/O operations are available
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
checks if end-of-file has been reached
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
checks if an error has occurred
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
checks if a non-recoverable error has occurred
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
checks if an error has occurred (synonym of
fail()
)
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
checks if no error has occurred (synonym of
!
fail()
)
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
returns state flags
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
sets state flags
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
modifies state flags
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
Formatting |
|
copies formatting information
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
manages the fill character
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
Miscellaneous |
|
manages exception mask
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
sets the locale
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
manages associated stream buffer
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
manages tied stream
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
narrows characters
(public member function of
std::basic_ios<CharT,Traits>
)
|
|
widens characters
(public member function of
std::basic_ios<CharT,Traits>
)
|
Inherited from std:: ios_base
Member functions
Formatting |
|
manages format flags
(public member function of
std::ios_base
)
|
|
sets specific format flag
(public member function of
std::ios_base
)
|
|
clears specific format flag
(public member function of
std::ios_base
)
|
|
manages decimal precision of floating point operations
(public member function of
std::ios_base
)
|
|
manages field width
(public member function of
std::ios_base
)
|
|
Locales |
|
sets locale
(public member function of
std::ios_base
)
|
|
returns current locale
(public member function of
std::ios_base
)
|
|
Internal extensible array |
|
[static]
|
returns a program-wide unique integer that is safe to use as index to
pword()
and
iword()
(public static member function of
std::ios_base
)
|
resizes the private storage if necessary and access to the
long
element at the given index
(public member function of
std::ios_base
)
|
|
resizes the private storage if necessary and access to the
void
*
element at the given index
(public member function of
std::ios_base
)
|
|
Miscellaneous |
|
registers event callback function
(public member function of
std::ios_base
)
|
|
[static]
|
sets whether C++ and C I/O libraries are interoperable
(public static member function of
std::ios_base
)
|
Member classes |
|
stream exception
(public member class of
std::ios_base
)
|
|
initializes standard stream objects
(public member class of
std::ios_base
)
|
Member types and constants |
|||||||||||||||||||||||||||||||||||||||
Type | Explanation | ||||||||||||||||||||||||||||||||||||||
stream open mode type
The following constants are also defined:
(typedef) |
|||||||||||||||||||||||||||||||||||||||
formatting flags type
The following constants are also defined:
(typedef) |
|||||||||||||||||||||||||||||||||||||||
state of the stream type
The following constants are also defined:
(typedef) |
|||||||||||||||||||||||||||||||||||||||
seeking direction type
The following constants are also defined:
(typedef) |
|||||||||||||||||||||||||||||||||||||||
specifies event type
(enum) |
|||||||||||||||||||||||||||||||||||||||
callback function type
(typedef) |
Notes
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_syncbuf
|
201803L | (C++20) |
Synchronized buffered ostream (
std::osyncstream
,
std::syncbuf
) and manipulators
|