| I/O manipulators | ||||
| Print functions(C++23) | ||||
| C-style I/O | ||||
| Buffers | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++20) | ||||
| Streams | ||||
| Abstractions | ||||
| File I/O | ||||
| String I/O | ||||
| Array I/O | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
| Synchronized Output | ||||
(C++20) | ||||
| Types | ||||
| Error category interface | ||||
(C++11) | ||||
(C++11) |
| Member functions | ||||
(C++11) | ||||
(C++11) | ||||
| File operations | ||||
basic_ofstream::is_open | ||||
| Non-member functions | ||||
(C++11) |
bool is_open()const; | ||
Checks if the file stream has an associated file.
Effectively callsrdbuf()->is_open().
Contents |
(none)
true if the file stream has an associated file,false otherwise.
| This section is incomplete Reason: no example |
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 365 | C++98 | is_open was not declared withconst qualifier | declared withconst qualifier |
| opens a file and associates it with the stream (public member function)[edit] | |
| closes the associated file (public member function)[edit] |
