It's been so long since I've had to use OOP in D that I'm starting to forget things like this. If I have the parent class A which defines a constructor:

class A
{
    string val;

    this(string val) { this.val = val; }
}

And a child class B which inherits from A:

class B: A
{
}

I get the the following error:

Error: class B cannot implicitly generate a default ctor when base class A is missing a default ctor

Is there a simpler way to do this without having to define a constructor in B that just forwards to A's constructor, like so?

class B: A
{
    this(string val) { super(val); }
}

Is it allowed to do something like `alias __ctor = super.__ctor`?

no and no. howewer, creating template mixin with default ctors may spare you of some typing.

On Tue, Jun 21, 2016 at 02:48:39AM +0000, ketmar via Digitalmars-d-learn wrote:
> no and no. howewer, creating template mixin with default ctors may spare you of some typing.

I think Phobos has an AutoImplement template that might do this for you. Maybe take a look in std.typecons or std.meta (or wherever they shove those things these days)?


T

-- 
"Hi." "'Lo."

On Tuesday, 21 June 2016 at 03:06:22 UTC, H. S. Teoh wrote:
> On Tue, Jun 21, 2016 at 02:48:39AM +0000, ketmar via Digitalmars-d-learn wrote:
>> no and no. howewer, creating template mixin with default ctors may spare you of some typing.
>
> I think Phobos has an AutoImplement template that might do this for you. Maybe take a look in std.typecons or std.meta (or wherever they shove those things these days)?
>
>
> T

I was going to say that this is painful compared to Java or C++, but it looks like it's been too long since I've used those languages as well; neither of them allow constructor inheritance (but C++ has a syntax for doing it explicitly).