How does one construct a mask for the MS bit?

[P. Tucker Withington]

>> This would require generation of a mask for the most significant bit

It should be easy to make a constant that masks a machine's "high" bit, but
as I mentioned a while back, ~(~(unsigned)0>>1) croaks pcc in a static
declaration; apparently because it does not know how to simplify casts in a
constant.  (It works fine as auto or in an expression, but then you're doing
unnecessary work at run time, especially if you made it a #define.)

The only feedback I got was that you "should" be allowed to have casts in a
constant; that they were "accidentally" left out of K&R...

                               o.o      --tucker
                                ~