subtypes of restricted parametric types are unrestricted

[StefanKarpinski]

I can see that it would be annoying to enforce this, but it seems bad:

julia> abstract Pointy{T<:Real}

julia> type Point{T} <: Pointy{T}
         x::T
         y::T
       end

julia> Pointy{String}
type error: Pointy: in T, expected Real, got AbstractKind

julia> Point{String}
Point{String}

Can subtypes inherit restrictions on their type parameters from their supertype?

[JeffBezanson]

Yes, it should be an error to instantiate Pointy{T} in the definition of Point since T does not match Pointy's parameter.

[JeffBezanson]

I think I decided that Pointy{T} is ok since people like to write things like Complex{T} in method signatures without worrying about it, but Point{String} should give an error. That's OK since it makes sense to say a method matches Pointy with any parameter type, even though you can only actually make Pointy instances with valid parameters <:Real.