On Thu, 07 Jul 2011 11:38:05 -0400, teo <teo.ubu...@yahoo.com> wrote:
On Wed, 06 Jul 2011 16:21:31 +0200, Trass3r wrote:
Am 06.07.2011, 16:15 Uhr, schrieb teo <teo.ubu...@yahoo.com>:
What is the best way to translate following to D?
#define MAKELONG(a, b) \
((LONG) (((WORD) (a)) | ((DWORD) ((WORD) (b))) << 16))
The point is I would like to be able to use that at compile-time. The
macro is supposed to define some constants.
Just turn it into a function.
If you assign it to an enum or use it as an initializer for global
immutables it should be evaluated at compile-time.
Thank you. That did the trick.
However I am facing another problem:
There is a macro, which obtains the size of a type
#define TYPESIZE(t) (sizeof(t))
Well, I can't really say I understand the point of using this macro at
all. sizeof is a builtin, and part of the C spec. Why not just use
sizeof?
In d it's t.sizeof.
Example:
printf("%ld\n", TYPESIZE(short));
printf("%ld\n", TYPESIZE(struct A));
printf("%ld %ld\n", short.sizeof, A.sizeof);
The TYPESIZE macro is used within another macro which defines constants.
#define M(a,b,size) \
((a) << SHIFT_A) | \
((b) << SHIFT_B) | \
((size) << SHIFT_SIZE))
#define MM(a,b,type) M((a),(b),(TYPESIZE(type)))
Define MM and M as normal functions as Trass3r suggested, then use
type.sizeof.
Example:
#define C1 MM(1, 2, struct A)
#define C2 MM(3, 4, struct B)
Note, in D, to ensure compile-time evaluation, it's useful to have a
template that does this:
template MM(uint a, uint b, T)
{
enum MM = (a << SHIFT_A) | (b << SHIFT_B) | (T.sizeof << SHIFT_SIZE);
}
Usage is like:
enum C1 = MM!(1, 2, A);
enum C2 = MM!(3, 4, B);
