std::basic_filebuf<CharT,Traits>::close
| std::basic_filebuf<CharT, Traits>* close(); |
||
If a put area exist (e.g. file was opened for writing), first calls overflow(Traits::eof()) to write all pending output to the file, including any unshift sequences.
If the most recently called function, out of underflow(), overflow(), seekpos(), and seekoff(), was overflow(), then calls std::codecvt::unshift(), perhaps multiple times, to determine the unshift sequence according to the imbued locale, and writes that sequence to file with overflow(Traits::eof()).
Then, closes the file as if by calling std::fclose(), regardless of whether any of the preceding calls succeeded or failed.
If any of the function calls made, including the call to std::fclose(), fails, returns a null pointer. If any of the function calls made throws an exception, the exception is caught and rethrown after closing the file. If the file is already closed, returns a null pointer right away.
In any case, updates the private member variable that is accessed by is_open().
Parameters
(none)
Return value
this on success, a null pointer on failure.
Notes
close() is typically called through the destructor of std::basic_filebuf (which, in turn, is typically called by the destructor of std::basic_fstream.
Example
| This section is incomplete Reason: no example |
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 443 | C++98 | the file was written using overflow(EOF) | changed to overflow(Traits::eof()) |
| LWG 622 | C++98 | it was unclear how to handle the exception thrown during closing |
it is rethrown after closing the file |
See also
| checks if the associated file is open (public member function) | |
| [virtual] |
destructs a basic_filebuf object and closes the file if it is open (virtual public member function) |