Subtyping is wrong (because of variable bounds?)

[ulysses4ever]

Julia used to say true (e.g. in 0.6.2) here:

Ref{Union{Int64, Ref{Number}}} <: Ref{Union{Ref{T}, T}} where T

but current master, quite reasonably, says false. If you change, though, Ref to Val it is true again:

Ref{Union{Val{Number}, Int64}} <: Ref{Union{Val{T}, T}} where T

Which seems to be a bug.

[JeffBezanson]

Seems to be related to Ref being an abstract type.

[JeffBezanson]

...which affects the order of the Union components. When the types "line up":

Ref{Union{Val{Number}, Int64}} <: Ref{Union{Val{T}, T}} where T

then we say true, but with the other order on the left:

Ref{Union{Int64, Val{Number}}} <: Ref{Union{Val{T}, T}} where T

we say false.