Wrong overload resolution

[Baz via Digitalmars-d-learn]

On Sunday, 15 February 2015 at 23:48:50 UTC, rumbu wrote:
>
> This problem appears only if one of the parameters is an 
> interface. Without it or using any other type as a second 
> parameter instead of the interface, it compiles. Also it 
> compiles if the passed interface is null. The example below 
> uses short/ushort, but I found the same behaviour for any 
> combination of integral types of the same bitsize 
> (byte/ubyte/char, ushort/short/wchar, int/uint/dchar, 
> long/ulong)
>
> D 2.066.1
>
> interface I {}
> class C: I {}
>
> void func(ushort s, I i)
> {
>     writeln("ushort overload");
> }
>
> void func(short s, I i)
> {
>     writeln("short overload");
> }
>
> void call(short s)
> {
>     C c = new C();
>     I d = new C();
>     func(s, c); // ---- ERROR ---- see below
>
>     //but these are ok
>
>     func(s, cast(I)c) //ok
>     func(s, d) //ok
>     func(s, null) //ok
>
> }
>
> main.func called with argument types (short, C) matches both:	
> main.func(short s, I i)	
> main.func(ushort s, I i)

it's intereting to note that if func() are rewritten:

---
void func(ref ushort s, I i){}
void func(ref short s, I i){}
---

or even

---
void func(const ref ushort s, I i){}
void func(const ref short s, I i){}
---

the problem doesn't happend.