Alias this and opDispatch override

[Domain]

On Friday, 7 September 2018 at 02:22:58 UTC, Domain wrote:
> The following code fail to compile:
>
> enum KeyMod : int
> {
>     LCtrl  = 1 << 0,
>     RCtrl  = 1 << 1,
>     Ctrl   = LCtrl | RCtrl,
> }
>
> struct Flags(E)
> {
> public:
>     BitFlags!(E, Yes.unsafe) flags;
>     alias flags this;
>
>     bool opDispatch(string name)() const
>     if (__traits(hasMember, E, name))
>     {
>         enum e = __traits(getMember, E, name);
>         return (mValue & e) != 0;
>     }
> }
>
> Flags!KeyMod keys;
> keys.LCtrl = true;
> assert(keys.Ctrl);
>
> Error: no property LCtrl for type Flags!(KeyMod)
> Error: no property Ctrl for type Flags!(KeyMod)

Sorry. This works:

struct Flags(E)
{
public:
     BitFlags!(E, Yes.unsafe) flags;
     alias flags this;

     bool opDispatch(string name)() const
     if (__traits(hasMember, E, name))
     {
         enum e = __traits(getMember, E, name);
         return cast(int)(flags & e) != 0;
     }

     void opDispatch(string name)(bool set)
     if (__traits(hasMember, E, name))
     {
         enum e = __traits(getMember, E, name);
         if (set)
             flags |= e;
         else
             flags &= ~e;
     }
}