type-intersection environment bug

[vtjnash]

The result is missing the where T

julia> z2(::Type{T} where T<:Tuple{Vararg{S}}) where {S} = S
z2 (generic function with 1 method)

julia> z2(Tuple{Vararg{Complex{T}}} where T)
Complex{T}

[vtjnash]

When this is fixed, the method

essentials.jl:69
convert(::Type{Tuple{Vararg{T}}}, x::Tuple) where {T} = cnvt_all(T, x...)

Should be re-written with the above form, so that it accepts any NTuple, and not just ones where N is unknown. For example, Tuple{Complex, Vararg{Complex}} and Tuple{Complex, Complex} should both also work with calling this method.

[JeffBezanson]

Yes, the free typevar there is definitely a bug.

We also have this behavior:

julia> Tuple{Complex,Complex} <: NTuple
false

Basically NTuple is a "diagonal" type. So I'm not sure those types would(/should) match this method.

[vtjnash]

Oops, that wasn't supposed to be a diagonal type, I copied the wrong example. The types should have been constrained to be the same: Tuple{Complex{T}, Complex{T}} where T like in the OP.

[JeffBezanson]

This is now a method error. Fixed by #23691 and #23643?

[vtjnash]

SGTM