std::basic_istream< _CharT, _Traits >::sentry(3)      Library Functions Manual

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::basic_ios< _CharT, _Traits
       >::good(), and std::ios_base::goodbit.

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.

                                   libstdc++
                              std::basic_istream< _CharT, _Traits >::sentry(3)