basic_ostream::sentry Class Reference

Performs setup work for output streams. More...

List of all members.

Public Member Functions


Detailed Description

template<typename _CharT, typename _Traits>
class std::basic_ostream< _CharT, _Traits >::sentry

Objects of this class are created before all of the standard inserters are run. It is responsible for "exception-safe prefix and suffix operations." Additional actions may be added by the implementation, and we list them in http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5 under [27.6] notes.

Definition at line 355 of file ostream.


Constructor & Destructor Documentation

sentry ( basic_ostream< _CharT, _Traits > &  __os  )  [inline, explicit]

The constructor performs preparatory work.

Parameters:
os The output stream to guard.
If the stream state is good (os.good() is true), then if the stream is tied to another output stream, is.tie()->flush() is called to synchronize the output sequences.

If the stream state is still good, then the sentry state becomes true ("okay").

Definition at line 51 of file ostream.tcc.

References ios_base::failbit, basic_ios::good(), basic_ios::setstate(), and basic_ios::tie().

~sentry (  )  [inline]

Possibly flushes the stream.

If ios_base::unitbuf is set in os.flags(), and std::uncaught_exception() is true, the sentry destructor calls flush() on the output stream.

Definition at line 383 of file ostream.

References ios_base::badbit, std::uncaught_exception(), and ios_base::unitbuf.


Member Function Documentation

operator bool (  )  const [inline]

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).

Definition at line 401 of file ostream.


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

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