std::basic_fstream<CharT,Traits>::is_open
bool is_open(); |
(until C++11) | |
bool is_open() const; |
(since C++11) |
Checks if the file stream has an associated file.
Effectively calls rdbuf()->is_open().
Parameters
(none).
Return value
true if the file stream has an associated file, false otherwise.
Example
#include <string>
#include <fstream>
#include <iostream>
int main()
{
std::string filename = "some_file";
std::fstream fs(filename, std::ios::in);
std::cout << std::boolalpha;
std::cout << "fs.is_open() = " << fs.is_open() << '\n';
if(!fs.is_open())
{
fs.clear();
fs.open(filename, std::ios::out);
std::cout << "fs.is_open() = " << fs.is_open() << '\n';
}
}
Possible output:
fs.is_open() = false fs.is_open() = true
See also
| opens a file and associates it with the stream (public member function) |
|
| closes the associated file (public member function) |
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