std::basic_ist...raits >::sentry(3cxx) std::basic_ist...raits >::sentry(3cxx)
NAME
std::basic_istream< _CharT, _Traits >::sentry - Performs setup work for
input streams.
SYNOPSIS
#include <istream>
Public Types
typedef __istream_type::__ctype_type __ctype_type
typedef _Traits::int_type __int_type
typedef basic_istream< _CharT, _Traits > __istream_type
typedef basic_streambuf< _CharT, _Traits > __streambuf_type
typedef _Traits traits_type
Easy access to dependent types.
Public Member Functions
sentry (basic_istream< _CharT, _Traits > &__is, bool __noskipws=false)
The constructor performs all the work.
operator bool () const
Quick status checking.
Detailed Description
template<typename _CharT, typename _Traits>
class std::basic_istream< _CharT, _Traits >::sentry"Performs setup work
for input streams.
Objects of this class are created before all of the standard extractors
are run. It is responsible for exception-safe prefix and suffix
operations, although only prefix actions are currently required by the
standard.
Member Typedef Documentation
template<typename _CharT , typename _Traits > typedef _Traits
std::basic_istream< _CharT, _Traits >::sentry::traits_type
Easy access to dependent types.
Constructor & Destructor Documentation
template<typename _CharT , typename _Traits > std::basic_istream< _CharT,
_Traits >::sentry::sentry (basic_istream< _CharT, _Traits > & __is, bool
__noskipws = false) [explicit]
The constructor performs all the work.
Parameters
__is The input stream to guard.
__noskipws Whether to consume whitespace or not.
If the stream state is good (__is.good() is true), then the following
actions are performed, otherwise the sentry state is false (not okay)
and failbit is set in the stream state.
The sentry's preparatory actions are:
1. if the stream is tied to an output stream, is.tie()->flush() is
called to synchronize the output sequence
2. if __noskipws is false, and ios_base::skipws is set in is.flags(),
the sentry extracts and discards whitespace characters from the
stream. The currently imbued locale is used to determine whether
each character is whitespace.
If the stream state is still good, then the sentry state becomes true
(okay).
References std::ios_base::badbit, std::ios_base::eofbit,
std::ios_base::failbit, std::ios_base::goodbit, and
std::ios_base::skipws.
Member Function Documentation
template<typename _CharT , typename _Traits > std::basic_istream< _CharT,
_Traits >::sentry::operator bool () const [inline], [explicit]
Quick status checking.
Returns
The sentry state.
For ease of use, sentries may be converted to booleans. The return value
is that of the sentry state (true == okay).
Author
Generated automatically by Doxygen for libstdc++ from the source code.
libstdstd::basic_ist...raits >::sentry(3cxx)
Generated by dwww version 1.16 on Sat Oct 3 06:00:47 CEST 2026.