std::emit_on_flush, std::noemit_on_flush

 

C++

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Feature test macros (C++20)

Language support library

Concepts library (C++20)

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Filesystem library (C++17)

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Technical specifications

Symbols index

External libraries

 

Input/output library

I/O manipulators

Print functions (C++23)

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

basic_spanbuf (C++23)

strstreambuf (C++98/26*)

basic_syncbuf (C++20)

Streams

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ios_base

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basic_stringstream

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basic_ispanstream (C++23)

basic_ospanstream (C++23)

basic_spanstream (C++23)

istrstream (C++98/26*)

ostrstream (C++98/26*)

strstream (C++98/26*)

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_flushnoemit_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>& noemit_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<CharT,Traits,Allocator>)