std::emit_on_flush, std::no_emit_on_flush

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (deprecated in C++98)

basic_syncbuf (C++20)

Streams

Abstractions

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I/O

basic_ifstream

basic_ofstream

basic_fstream

String I/O

basic_istringstream

basic_ostringstream

basic_stringstream

Array I/O

istrstream (deprecated in C++98)

ostrstream (deprecated in C++98)

strstream (deprecated in C++98)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

 

Input/output manipulators

Floating-point formatting
showpointnoshowpoint setprecision	fixedscientifichexfloatdefaultfloat (C++11)(C++11)
Integer formatting
setbase showbasenoshowbase	dechexoct
Boolean formatting
boolalphanoboolalpha
Field width and fill control
setfill setw	internalleftright
Other formatting
showposnoshowpos	uppercasenouppercase
Whitespace processing
ws ends	skipwsnoskipws
Output flushing
flush endl flush_emit (C++20)	unitbufnounitbuf emit_on_flushno_emit_on_flush (C++20)(C++20)
Status flags manipulation
resetiosflags	setiosflags
Time and money I/O
get_money (C++11) get_time (C++11)	put_money (C++11) put_time (C++11)
Quoted manipulator
quoted (C++14)

 

Defined in header <ostream>
template< class CharT, class Traits > std::basic_ostream<CharT, Traits>& emit_on_flush( std::basic_ostream<CharT, Traits>& os );	(1)	(since C++20)
template< class CharT, class Traits > std::basic_ostream<CharT, Traits>& no_emit_on_flush( std::basic_ostream<CharT, Traits>& os );	(2)	(since C++20)

If os.rdbuf() actually points to a std::basic_syncbuf<CharT, Traits, Allocator> buf, toggles whether it emits (i.e., transmits data to the underlying stream buffer) when flushed:

1) calls buf.set_emit_on_sync(true)

2) calls buf.set_emit_on_sync(false)

Otherwise, these manipulators have no effect.

This is an output-only I/O manipulator, it may be called with an expression such as out << std::emit_on_flush for any out of type std::basic_ostream.

Parameters

os

-

reference to output stream

Return value

os (reference to the stream after manipulation)

See also

set_emit_on_sync

changes the current emit-on-sync policy (public member function of std::basic_syncbuf)