Question

i was testing with flags in file stream objects the other day

And i did this.

fstream binf("h.txt", ios::app);
binf << "hey";

With fstream since i didnt use ios::out, the output operation shouldnt have worked , but it does work

I noticed that the the output operation works with ios::app only but if i use any other flag without ios::out it doesnt work

Can anyone tell me why I was able to output to the file while using only ios::app without ios::out

Answer 1

Using app implies out.

The standard specifies that app and out|app have the same result, equivalent to C fopen in mode "a".