Fri, 24 Jul 2009 09:07:30 -0400, Steven Schveighoffer wrote:
> On Thu, 23 Jul 2009 22:09:12 -0400, Sergey Gromov <snake.sc...@gmail.com>
> wrote:
>
>> Thu, 23 Jul 2009 11:54:40 -0400, Steven Schveighoffer wrote:
>>
>>> LOOKUP_TABLE[0] = Method("method1", &Component.method1);
>>> LOOKUP_TABLE[1] = Method("method2", &Component.method2);
>>
>> These two lines are weird. ``pragma(msg)`` shows that type of
>> ``&method1`` is ``void function()`` while it must be ``void delegate()``
>> for a non-static member because of difference in calling convention.
>> Actually I think that taking an address of a non-static member in a
>> static context must be a compile time error.
>
> It's because I'm taking the address of the function on the type, not on an
> instance. It's not a delegate because there's no "this" pointer yet.
>
> It makes sense to me anyways. A delegate is a normal function pointer
> coupled with a hidden context parameter.
The ``Type.`` part does not change anything. It simply directs compiler
to use overloads from a particular class hierarchy level. Here:
static Method[] LOOKUP_TABLE2 = [
{ name : "method1", method : &Component.method1 },
{ name : "method2", method : &method2 }
];
This code compiled with DMD 1.046 gives the following errors:
test2.d(30): Error: non-constant expression & method1
test2.d(30): Error: non-constant expression & method2
Also if you add this code:
pragma(msg, "outside: " ~ typeof(&method1).stringof);
void method1() { writefln("method1");
pragma(msg, "inmeth: " ~ typeof(&method1).stringof);
}
you get:
outside: void function()
inmeth: void delegate()
So the type of a non-static method address taken in a static context is
obviously wrong.
