Hello John,
Hello tim,
On Sun, 25 Jan 2009 16:43:55 +1300, John Reimer
<terminal.n...@gmail.com> wrote:
With this code:
--------------------------------
module test5;
interface I
{
void foo();
}
class A : I {
void foo() { }
}
class B : A, I
{
alias A.foo foo;
}
void main()
{
}
--------------------------------
I get this error:
--------------------------------
class test5.B interface function I.foo is not implemented
--------------------------------
Does this make sense? I mean, shouldn't the explicit reuse of A.foo
in B be sufficient indication to the compiler that B is satisfying
the contract I? I'm hoping to make use of such subtleties in some
code, but first I have to understand the reasoning behind this. :)
Note that this works if I remove the interface I from B's
declaration -- ie "class B: A" -- since, in the D language, B is
not required to fulfull A's interface contract even though it
inherits from it. -JJR
It look like the real bug is re-allowing B to implement interface I
but
sometimes bug do get reported differently. Why don't you remove I
from
B's
declaration like you said that works. It actually says here
http://www.digitalmars.com/d/1.0/interface.html "Classes cannot
derive
from an interface multiple times."
Yes, please check the link again (further down the page). D allows
you to reimplement the interface as long as class B provides a new
implementation:
"A reimplemented interface must implement all the interface functions,
it does not inherit from a super class"...
That probably could be stated a little more clearly, but that's what
it says.
As for why I'm doing it, I assure you that there's a very specific
reason why I'm trying this: it is a possible interfacing mechansim for
ported software of a much more complicated nature than this simple
reduction; I reduced it to this in order to try to understand
potential iteractions between class and interface layers. The
question here was to figure out the reasoning behind the language
design, not necessarily whether I should be doing it or not. ;-)
-JJR
Hmmm, now that I think of it... given the context of my question, I probably
should have asked it in D newsgroup...
-JJR
