Add is_, as_ & extend Base.isreal & Base.real

for `AbstractPolynomial`s

Author: singularitti

src/abstract.jl

@@ -17,6 +17,13 @@ abstract type AbstractPolynomial{T} end
 # works for most cases
 ⟒(P::Type{<:AbstractPolynomial}) = constructorof(P)
 
+# See discussions in https://github.com/JuliaMath/Polynomials.jl/issues/258
+is_(fn, p::AbstractPolynomial) = all(fn, coeffs(p))
+as_(fn, p::P) where {P<:AbstractPolynomial} = ⟒(P)(fn.(coeffs(p)), p.var)
+
+Base.isreal(p::AbstractPolynomial) = is_(isreal, p)
+Base.real(p::P) where {P<:AbstractPolynomial}  = as_(real, p)
+
 """
     Polynomials.@register(name)