• Pavel (25/25) Jun 17 2014 Hello!
• Steven Schveighoffer (6/28) Jun 17 2014 b and c should be identical IMO. This means there are 2 entries for I
• rumbu (9/17) Jun 17 2014 If you swap the interfaces (class A: C, B), "a is b" will return

"Pavel" <phondogo gmail.com> writes:

Hello!

import std.stdio;

interface I {
	
}

interface B : I {
	void test();
}

interface C : I {
	void test1();
}

class A : B, C {
   override void test() {}
   override void test1() {}
}

void main() {
	A a = new A();
	I b = cast(B)a;
	I c = cast(C)a;

writeln(cast(void*)a, "  ", cast(void*)b, "  ", cast(void*)c); // 
1EE1FE0  1EE1FE8  1EE1FEC

assert (a is b); // OK
assert (a is c); // FAIL WHY????
	
}

"Steven Schveighoffer" <schveiguy yahoo.com> writes:

On Tue, 17 Jun 2014 15:02:33 -0400, Pavel <phondogo gmail.com> wrote:

 Hello!

 import std.stdio;

 interface I {
 	
 }

 interface B : I {
 	void test();
 }

 interface C : I {
 	void test1();
 }

 class A : B, C {
    override void test() {}
    override void test1() {}
 }

 void main() {
 	A a = new A();
 	I b = cast(B)a;
 	I c = cast(C)a;

 writeln(cast(void*)a, "  ", cast(void*)b, "  ", cast(void*)c); //  
 1EE1FE0  1EE1FE8  1EE1FEC

b and c should be identical IMO. This means there are 2 entries for I  
inside the object, which is a waste of space.

 assert (a is b); // OK

This should also fail. It seems like a bug to me. 'is' should compare  
pointers, not anything else.

-Steve

"rumbu" <rumbu rumbu.ro> writes:

On Tuesday, 17 June 2014 at 19:02:34 UTC, Pavel wrote:

 class A : B, C {
   override void test() {}
   override void test1() {}
 }

If you swap the interfaces (class A: C, B), "a is b" will return 
false, but "a is c" will return true. Clearly, this is a bug.

 void main() {
 	A a = new A();
 	I b = cast(B)a;
 	I c = cast(C)a;

If you remove the casts, will work as expected:

I b = a;
I c = a;

or even:

B b = a;
C c = a;