The "limits.h" (ISO C99 Standard) defines UINT_MAX as the maximum value for a variable of type unsigned int which is 4294967295 (0xffffffff).
"The contents of the header <limits.h> are given below, in alphabetical order. The minimum magnitudes shown shall be replaced by implementation-defined magnitudes with the same sign."
#define UINT_MAX 65535
Key here is implementation-defined, with a minimum of 65535.I always liked the definition of true in Forth (all bits set to 1). It really made it a lot easier.