31. cin interpretation of 0 and 0x prefixes

• 
      cin.unsetf( ios::dec ); // Interpret 0 and 0x as hexadecimal and octal prefixes
      cin.unsetf( ios::oct ); // Ignore octal prefix, interpret 077 as decimal 77
  
      cin.unsetf( ios::dec );
      cin.setf( ios::oct );   // All integers now expected to be octal base
  
      cin.unsetf( ios::dec );
      cin.setf( ios::hex );   // All integers now expected to be base-16:
  
  

• Sample program cin_setf.cpp ( download ) illustrates integer base/prefix manipulation and rudimentary format-related error recovery.

• See also cin.setf() and cin.unsetf() documentation.