On Mon, 24 Feb 2014 11:36:50 -0500, Frustrated <c1514...@drdrb.com> wrote:
http://dpaste.dzfl.pl/c25655e2dfe9
The code above simplifies using interfaces as the programming
object. It allows one to program the derived classes as if they
were not part of an abstraction by mapping the abstracted virtual
methods to concrete methods.
e.g.,
class WindowsGui : iGui
{
WindowsButton _button;
@property WindowsButton button(WindowsButton b) { return
(_button = b); }
mixin(Fixup!(WindowsGui, iButton, WindowsButton));
}
instead of
class WindowsGui : iGui
{
WindowsButton _button;
@property iButton button(iButton b)
{
assert(cast(WindowsButton)b !is null, `Invalid object
type dependency mismatch! Type: `~b.classinfo.name~` Type
Expected: WindowsButton`);
auto bb = cast(WindowsButton)b;
// do work with bb.
}
}
Nice work!
One problem with the template is that b.classinfo.name returns
the interface instead of the actual class.
Hm... classinfo (now typeid) should get the most derived type from an
instance. This may be a factor of it being an interface instance vs. a
class instance. A simple test:
Stevens-MacBook-Pro:~ steves$ cat testinterface.d
import std.stdio;
interface I
{
}
class C : I
{
}
void main()
{
I i = new C;
writeln(typeid(i).name);
writeln(typeid(cast(Object)i).name);
}
Stevens-MacBook-Pro:~ steves$ ./testinterface
testinterface.I
testinterface.C
Looks like that is the case. Note that classinfo is not part of the
language any more, and will likely be deprecated. typeid is the correct
mechanism to get the TypeInfo of a derived class.
I'm thinking this is incorrect, typeid should get the derived class type
IMO. It shouldn't be that difficult or costly for the compiler to do.
-Steve
