Checking if a file opened successfully with ifstream

Question

I have the following that will open a file for reading. However, I want to check to make sure that the file was open successfully, so I am using the fail to see if the flags

Answer 1

You have to call fail() on the stream object. A more idiomatic way of doing this is:

input_stream.open(_file_name.c_str(), ios::in);

if( ! input_stream ) {
    return -1;
}