[Issue 17462] New: Order of base interfaces affects compiler behavior

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=17462

          Issue ID: 17462
           Summary: Order of base interfaces affects compiler behavior
           Product: D
           Version: D2
          Hardware: x86_64
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: maximzms at gmail.com

Code:
--------------------
interface Marker {}
interface Foo { void foo(); }

interface FooMarked : Foo, Marker {}
interface MarkedFoo : Marker, Foo  {}

class Base : Foo { override void foo() {} }

class Derived1 : Base, FooMarked {} // Inherit Base.foo
class Derived2 : Base, MarkedFoo {} // Error!

void main() {}
--------------------

Compiler output:
--------------------
main.d(10): Error: class main.Derived2 interface function 'void foo()' is not
implemented
--------------------

The interface `Foo` in `Derived1` is silently inherited from `Base` while the
documentation [1] says: "A reimplemented interface must implement all the
interface functions, it does not inherit them from a super class".

Using swapped base interfaces in `Derived2` causes compilation error as
expected.

May be related to issue 15591.

[1] https://dlang.org/spec/interface.html

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