Question

Let’s say I have a file that has

100 text

If I try reading 2 numbers using ifstream, it would fail because text is not a number. Using fscanf I’ll know it failed by checking its return code:

if (2 != fscanf(f, "%d %d", &a, &b))
    printf("failed");

But when using iostream instead of stdio, how do I know it failed?

Answer 1

Its actually as (if not more) simple:

ifstream ifs(filename);
int a, b;
if (!(ifs >> a >> b))
   cerr << "failed";

Get used to that format, by the way. as it comes in very handy (even more-so for continuing positive progression through loops).