bad type inference for composition of ImmutablePolynomials

[nsajko]

julia> using Test, Polynomials

julia> p = ImmutablePolynomial((1,))
ImmutablePolynomial(1)

julia> @inferred p(p)
ERROR: return type ImmutablePolynomial{Int64, :x, 1} does not match inferred return type Any

Note that the type inference doesn't just fail, it fails completely, that is the inferred return type is Any.

[jverzani]

I'll have to keep on eye on how to improve this, currently on the WIP PR, I see:

julia> p = ImmutableDensePolynomial{StandardBasis}((3,))
ImmutableDensePolynomial(3)

julia> @inferred p(p)
ERROR: return type ImmutableDensePolynomial{StandardBasis, Int64, :x, 1} does not match inferred return type ImmutableDensePolynomial{StandardBasis, _A, :x} where _A

[nsajko]

Fixed in v4.0.0 🚀