std::basic_filebuf<CharT,Traits>::is_open
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< cpp | io | basic filebuf
C++
Input/output library
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(C++23) | ||||
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(C++11) |
std::basic_filebuf
| Public member functions | ||||
(C++11) | ||||
(C++11) | ||||
(C++26) | ||||
basic_filebuf::is_open | ||||
| Protected member functions | ||||
| Non-member functions | ||||
(C++11) |
| bool is_open() const; |
|
Returns true if the most recent call to open() succeeded and there has been no call to close() since then.
Contents |
[edit] Parameters
(none)
[edit] Return value
true if the associated file is open, false otherwise.
[edit] Notes
This function is typically called by std::basic_fstream::is_open().
[edit] Example
Run this code
#include <fstream> #include <iostream> int main() { std::ifstream fs("test.txt"); std::filebuf fb; fb.open("test.txt", std::ios_base::in); std::cout << std::boolalpha << "direct call: " << fb.is_open() << '\n' << "through streambuf: " << fs.rdbuf()->is_open() << '\n' << "through fstream: " << fs.is_open() << '\n'; }
Output:
direct call: true through streambuf: true through fstream: true
[edit] See also
| opens a file and configures it as the associated character sequence (public member function) [edit] | |
| flushes the put area buffer and closes the associated file (public member function) [edit] |
