Tuple(Enum, Enum) is inferred as Tuple(Symbol, Symbol)

[wooster0]

enum E
  A
  B
  C
end

[:a,
 :b,
 :c] of E

Compiles.

enum E
  A
  B
  C
end

[{:a, :a},
 {:b, :b},
 {:c, :c}] of Tuple(E, E)

Showing last frame. Use --error-trace for full trace.

error in line 7
Error: no overload matches 'Pointer(Tuple(E, E))#[]=' with types Int32, Tuple(Symbol, Symbol)

Overloads are:
 - Pointer(T)#[]=(offset, value : T)

Doesn't compile. But it should, I think.
They're inferred to be Symbols but they're actually Es. The Pointer thing in the error message is weird too.

Extracted from #7690 (comment).

[asterite]

No, sorry. It works for Array because arrays are expanded to []= calls and the symbol is autocasted to Enum. But autocasting isn't applied to things inside other things, in this case things inside a tuple.