std::basic_istream::sentry Class Reference

List of all members.

Public Types

Public Member Functions

Detailed Description

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

Easy access to dependant types.

Definition at line 645 of file istream.

Constructor & Destructor Documentation

std::basic_istream::sentry::sentry ( basic_istream< _CharT, _Traits > &  __is,
bool  __noskipws = false 
) [explicit]

The constructor performs all the work.

isThe input stream to guard.
noskipwsWhether 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).

Definition at line 49 of file istream.tcc.

References std::skipws(), std::basic_ios< _CharT, _Traits >::eof(), std::basic_streambuf::sgetc(), and std::basic_streambuf::snextc().

Member Function Documentation

std::basic_istream::sentry::operator bool ( ) const [inline, explicit]

Quick status checking.

The sentry state.

For ease of use, sentries may be converted to booleans. The return value is that of the sentry state (true == okay).

Definition at line 686 of file istream.

The documentation for this class was generated from the following files: