Auto mapping override ref property to field

[Thaina]

Since we have ref return feature. We now could use ref return property as abstract, virtual, or interface

So I think we could map those ref return property to field directly

interface IVec3
{
    ref float X { get; set; }
    ref float Y { get; set; }
    ref float Z { get; set; }
}

struct Vec3 : IVec3
{
    public float X,Y,Z;
}

[HaloFour]

How exactly would this be implemented? The CLR requires that the virtual members of an interface be overridden by compatible members on the implementing class. The class would still be required to have the property accessors. At best the compiler could explicitly auto-generate them:

struct Vec3 : IVec3 {
    public float X,Y,Z;

    ref float IVec.X {
        get { return this.X; }
        set { this.X = value; }
    }

    ref float IVec.Y {
        get { return this.Y; }
        set { this.Y = value; }
    }

    ref float IVec.Z {
        get { return this.Z; }
        set { this.Z = value; }
    }
}

But given that the auto-property implementation is not much more verbose does this really buy any advantages?

[Thaina]

Well I wish this feature would be support by CLR if needed. I'm not sure so I don't mention it. But not that kind of workaround for sure

[qrli]

As soon as you access a struct via interface or access a field by ref, the struct will be boxed first, so as to keep the reference valid. So, you are replacing a float value copy with a memory allocation, a whole struct copy, a pointer return, and derefencing operations. What's the benefit to use it?

[Thaina]

@qrli With generic constraint you don't boxed struct