Code:
----
import std.stdio;

interface A {
public:
	final void bar();
}

class B : A {
	
}

void main()
{
	
}
----

No message.
But:

----
import std.stdio;

interface A {
public:
	void bar();
}

class B : A {
	
}

void main()
{
	
}
----

Gives the correct error message:
Error: class B interface function 'void bar()' is not implemented

Bug or feature?

> Bug or feature?

You will get a linker error when you try to use the function.

This is a feature, because you can implement this function later or even in another module (and set mangling to match).

Example of the former:

-----
interface A {
public:
    final void bar();  // declaration

    /** ... */

    final void bar() { }  // implementation
}
-----

For the latter:

-----
interface A {
public:
    final void bar();
}

class B : A {
}

pragma(mangle, A.bar.mangleof)
void A_bar_impl(A _this) { }
-----

The mangle pragma feature is new in git-head.

On Tuesday, 10 September 2013 at 21:03:57 UTC, Andrej Mitrovic wrote:
>> Bug or feature?
>
> You will get a linker error when you try to use the function.
>
> This is a feature, because you can implement this function later or
> even in another module (and set mangling to match).
>
> Example of the former:
>
> -----
> interface A {
> public:
>     final void bar();  // declaration
>
>     /** ... */
>
>     final void bar() { }  // implementation
> }
> -----
>
> For the latter:
>
> -----
> interface A {
> public:
>     final void bar();
> }
>
> class B : A {
> }
>
> pragma(mangle, A.bar.mangleof)
> void A_bar_impl(A _this) { }
> -----
>
> The mangle pragma feature is new in git-head.

Ah, thanks for explanation.