.TH "std::basic_ostream< _CharT, _Traits >::sentry" 3cxx "Wed Jul 28 2021" "libstdc++" \" -*- nroff -*-
.ad l
.nh
.SH NAME
std::basic_ostream< _CharT, _Traits >::sentry \- Performs setup work for output streams\&.  

.SH SYNOPSIS
.br
.PP
.SS "Public Member Functions"

.in +1c
.ti -1c
.RI "\fBsentry\fP (\fBbasic_ostream\fP< _CharT, _Traits > &__os)"
.br
.RI "The constructor performs preparatory work\&. "
.ti -1c
.RI "\fB~sentry\fP ()"
.br
.RI "Possibly flushes the stream\&. "
.ti -1c
.RI "\fBoperator bool\fP () const"
.br
.RI "Quick status checking\&. "
.in -1c
.SH "Detailed Description"
.PP 

.SS "template<typename _CharT, typename _Traits>
.br
class std::basic_ostream< _CharT, _Traits >::sentry"
Performs setup work for output streams\&. 

Objects of this class are created before all of the standard inserters are run\&. It is responsible for \fIexception-safe prefix and suffix operations\fP\&. 
.PP
Definition at line 432 of file ostream\&.
.SH "Constructor & Destructor Documentation"
.PP 
.SS "template<typename _CharT , typename _Traits > \fBstd::basic_ostream\fP< _CharT, _Traits >::sentry::sentry (\fBbasic_ostream\fP< _CharT, _Traits > & __os)\fC [explicit]\fP"

.PP
The constructor performs preparatory work\&. 
.PP
\fBParameters\fP
.RS 4
\fI__os\fP The output stream to guard\&.
.RE
.PP
If the stream state is good (\fI__os\&.good()\fP is true), then if the stream is tied to another output stream, \fCis\&.tie()->flush()\fP is called to synchronize the output sequences\&.
.PP
If the stream state is still good, then the sentry state becomes true (\fIokay\fP)\&. 
.PP
Definition at line 46 of file ostream\&.tcc\&.
.PP
References std::ios_base::failbit, std::basic_ios< _CharT, _Traits >::good(), std::basic_ios< _CharT, _Traits >::setstate(), and std::basic_ios< _CharT, _Traits >::tie()\&.
.SS "template<typename _CharT , typename _Traits > \fBstd::basic_ostream\fP< _CharT, _Traits >::sentry::~sentry ()\fC [inline]\fP"

.PP
Possibly flushes the stream\&. If \fCios_base::unitbuf\fP is set in \fCos\&.flags()\fP, and \fCstd::uncaught_exception()\fP is true, the sentry destructor calls \fCflush()\fP on the output stream\&. 
.PP
Definition at line 462 of file ostream\&.
.SH "Member Function Documentation"
.PP 
.SS "template<typename _CharT , typename _Traits > \fBstd::basic_ostream\fP< _CharT, _Traits >::sentry::operator bool () const\fC [inline]\fP, \fC [explicit]\fP"

.PP
Quick status checking\&. 
.PP
\fBReturns\fP
.RS 4
The sentry state\&.
.RE
.PP
For ease of use, sentries may be converted to booleans\&. The return value is that of the sentry state (true == okay)\&. 
.PP
Definition at line 484 of file ostream\&.

.SH "Author"
.PP 
Generated automatically by Doxygen for libstdc++ from the source code\&.