Re: shifting bits

[fmdf@tiscali.it (fabio de francesco)]

Jim Rogers <jimmaureenrogers@worldnet.att.net> wrote in message news:<Xns9553DDDC8BEA9jimmaureenrogers@204.127.36.1>...
> fmdf@tiscali.it (fabio de francesco) wrote in 
> news:ba2f9c57.0408281738.61a48643@posting.google.com:
> 
> > 2) Can only variables of modular type be shifted ? If yes, why ?
> 
> Even in C and C++ bit shifting is only correct for unsigned types.
> Think about what would happen if you shift a sign bit. The 
> resulting values would be really nasty depending upon the state of
> the sign bit.
> 
> Modular types are Ada's unsigned types.
> 
> Jim Rogers

Talking about C/C++ you may want to shift a signed numeric variable
one position by one to the right in order to either inspect or print
each single bit that composes the number.

In low-level code, If you know what you are shifting and why, you
won't have any bad result. May be that I'm used to Assembly where you
often do shifting with every type of value for the most unthinkable
reason.

Regards,
Fabio De Francesco