Robust cin integer read equivalent to scanf re-prompt loop

To make cin>>x reject non-numeric input like a validated scanf loop: while(true){cout<<prompt; if(cin>>x) return x; if(cin.eof()){exit(0);} cin.clear(); cin.ignore(100000,\u0027\n\u0027); cout<<"enter a number";}. cin.clear() resets the failbit and cin.ignore() drops the stuck bad token, otherwise the same non-numeric char re-fails every subsequent read. This is the direct C++ port of the scanf(%d)!=1 + getchar-flush pattern and preserves identical behavior when porting printf/scanf code to iostream.