std::basic_filebuf::is_open
From cppreference.com
< cpplrm; | iolrm; | basic filebuf
| bool is_open() const; |
||
Returns true if the most recent call to open() succeeded and there has been no call to close() since then.
Parameters
(none)
Return value
true if the associated file is open, false otherwise.
Notes
This function is typically called by std::basic_fstream::is_open().
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
See also
| opens a file and configures it as the associated character sequence (public member function) | |
| flushes the put area buffer and closes the associated file (public member function) |