Hello, I have this code:

immutable class Base
{
	this() {}
}

immutable class Derived : Base {}

void main()
{
	new immutable Derived();
}

I'd like class Derived to automatically inherit the default constructor from Base. However, this is not the case:

main.d(6): Error: class main.Derived cannot implicitly generate a default ctor when base class main.Base is missing a default ctor

Is it a bug or it should be like this?

On Wednesday, 19 July 2017 at 16:00:56 UTC, Piotr Mitana wrote:
> Hello, I have this code:
>
> immutable class Base
> {
> 	this() {}
> }
>
> immutable class Derived : Base {}
>
> void main()
> {
> 	new immutable Derived();
> }
>
> I'd like class Derived to automatically inherit the default constructor from Base. However, this is not the case:
>
> main.d(6): Error: class main.Derived cannot implicitly generate a default ctor when base class main.Base is missing a default ctor
>
> Is it a bug or it should be like this?

I'd say it's a bug. There was a similar issue at one point where it wouldn't consider default constructor with default args.

On Wednesday, 19 July 2017 at 16:00:56 UTC, Piotr Mitana wrote:
> Hello, I have this code:
>
> immutable class Base
> {
> 	this() {}
> }
>
> immutable class Derived : Base {}
>
> void main()
> {
> 	new immutable Derived();
> }
>
> I'd like class Derived to automatically inherit the default constructor from Base. However, this is not the case:
>
> main.d(6): Error: class main.Derived cannot implicitly generate a default ctor when base class main.Base is missing a default ctor
>
> Is it a bug or it should be like this?

Interesting that the same code without immutable works.

On Wednesday, 19 July 2017 at 16:00:56 UTC, Piotr Mitana wrote:
> Hello, I have this code:
>
> immutable class Base
> {
> 	this() {}
> }
>
> immutable class Derived : Base {}
>
> void main()
> {
> 	new immutable Derived();
> }
>
> I'd like class Derived to automatically inherit the default constructor from Base. However, this is not the case:
>
> main.d(6): Error: class main.Derived cannot implicitly generate a default ctor when base class main.Base is missing a default ctor
>
> Is it a bug or it should be like this?

compiles with:
dmd 2.073

fails with:
dmd 2.074
dmd 2.075