But it is prone to accidental errors while setting the flags. It is basically possible to never use ifstream and ofstream and always use fstream with the required flags.

Ofstream outfile('filepath', ios::trunc) // Open the file for writing and clear its contents, ios::out is implicitly setįstream inoutfile('filepath') // default flag will be: ios::in | ios::out hence both reads and writes possibleįstream infile('filepath', ios::in) // file will be opened in read mode like fstream It reads whatever data is available.' With the MSDN example try typing less characters than it says, for example abc. You can do so in the constructor or when calling open(): ifstream infile('filepath', ios::binary) //Open the file for reading in binary mode, ios::in will always be set The difference is stated in the MSDN documentation: 'This function does not wait for input. But if you specify a flag explicitly for fstream like ios::in, it will be opened only for reading, like an ifstream.

On the other hand, if you do not pass any flags to fstream, the default is ios::in | ios::out, so you can read from as well as write to the file. 2 Comments 2 Solutions 12752 Views Last Modified.

Any other flags added will be combined with ios::in for ifstream and ios::out for ofstream Let me explain the difference between opening a file in text mode versus binary mode. Similary, ofstream always has the ios::out flag set and it cannot be removed. For example, it is the only way to test for the existence of a file.

ifstream always has the ios::in flag set and it cannot be removed.If I want to open the file in binary mode and append, I can combine the flags as follows: ios::binary | ios::app exchanged with other users of the streambuf (such as istream or ifstream). These flags are additive which means you can combine multiple flags using the bitwise OR | operator. Class RWpistream specializes the abstract base class RWvistream to restore. All write operations must occur at the end of the fileĮmpty the contents of the file after opening

Difference between istream and ifstream