On Tue, 10 Feb 2009 17:14:00 +0300, Don <nos...@nospam.com> wrote:
Derek Parnell wrote:
On Tue, 10 Feb 2009 13:08:03 +0100, Don wrote:
A&&B is not so terrible, since you can do it by nesting, as above.
The big problem is A || B. It creates a mess.
version(A) version = AorB;
version(B) version = AorB;
version(AorB) {
. . .
}
Yes. And that sucks, because you've got the version statement in two
places. And you've had to create an essentially meaningless temporary.
[1] Then when you have a more complex expression, especially where A and
B appear more than once, it gets disgusting.
[1] I know Walter's idea is that you create meaningful identifiers, but
in practice this kind of versioning can be a workaround. EG B is
"everything except WindowsME".
Version has so many shortcomings that it should definitely be redesigned.
My biggest complaint is that code inside version () {} block should be
semantically correct. It creates many obstacles and disallows good
use-cases:
- you cannot mix D1, D2 and (in future) D3 in a single source code file
without helf of mixins.
- you cannot mix asm for different platforms in one source code file
(because DMD doesn't understand ARM assembly, for instance)
- etc
Other use-case I came across recently reading .NET Framework source code:
class String :
IFoo,
IBar,
IBaz,
#if SUPPORT_GENERICS
IComparable<Foo>,
#endif
IWhee
{
// *very* large amount of code
}
How would you port it to D without code duplication and meaningless
intermediate classes?
