one's complement operator in Ada

one's complement operator in Ada

[Ding-yuan Sheu]

Hello all,

	I am working on a project to convert a C++ program into Ada95.
I try to find a easy way to achieve the effect of '~' (one's complement
operator) in C++. I wonder if there is a good way to obtain the same
result in Ada without programming it as a procedure or function.

For example, in C++:

	ulong  mask;
		:
		:

	ulong j:= ~mask;

How can I convert this partical code into Ada in a "easy" way?
I'll appreciate any help. Thanks in advance.


		Steven ( dsheu@afit.af.mil )

Re: one's complement operator in Ada

[Tucker Taft]

Ding-yuan Sheu (dsheu@afit.af.mil) wrote:


: 	I am working on a project to convert a C++ program into Ada95.
: I try to find a easy way to achieve the effect of '~' (one's complement
: operator) in C++. I wonder if there is a good way to obtain the same
: result in Ada without programming it as a procedure or function.

The "not" operator on modular integer types (presuming the
modulus is a power of 2) is equivalent to one's complement.

: For example, in C++:

: 	ulong  mask;
: 		:
: 		:

: 	ulong j:= ~mask;

: How can I convert this partical code into Ada in a "easy" way?

    type Unsigned_Long is mod 2**32;

        ...

    Mask : Unsigned_Long;

        ...

    J : Unsigned_Long := not Mask;

: I'll appreciate any help. Thanks in advance.

I hope the above helps.  In general, the bit-wise operators ~, &, |, ^
in C/C++ map directly to "not", "and", "or", and "xor" in Ada 95,
and are defined for boolean, array-of-boolean, and modular.

: 		Steven ( dsheu@afit.af.mil )

-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
Intermetrics, Inc.  Cambridge, MA  USA

Re: one's complement operator in Ada

[Laurent Guerby]

Steven> For example, in C++:

Steven> 	ulong mask;

Steven> 	ulong j:= ~mask;

   For example, in Ada 95:

   type U_Long is mod 2 ** 32;
   --  or use Interfaces.Unsigned_32

   Mask : U_Long;

   J : U_Long := not Mask;

   Question, how do you do easily a mask rotation in C? In Ada 95,
you just use Interfaces.Rotate_Left (or Right).

-- 
Laurent Guerby <guerby@gnat.com>, Team Ada.
   "Use the Source, Luke. The Source will be with you, always (GPL)."