overload Base.real for some differentials

Author: simeonschaub

src/differentials.jl

@@ -148,6 +148,7 @@ Base.Broadcast.broadcastable(::Zero) = Ref(Zero())
 Base.iterate(x::Zero) = (x, nothing)
 Base.iterate(::Zero, ::Any) = nothing
 
+Base.real(::Zero) = Zero()
 
 #####
 ##### `DNE`
@@ -189,6 +190,7 @@ Base.Broadcast.broadcastable(::One) = Ref(One())
 Base.iterate(x::One) = (x, nothing)
 Base.iterate(::One, ::Any) = nothing
 
+Base.real(::One) = One()
 
 #####
 ##### `AbstractThunk
@@ -216,6 +218,8 @@ wirtinger_primal(::Union{AbstractThunk}) =
 wirtinger_conjugate(::Union{AbstractThunk}) =
     throw(ArgumentError("`wirtinger_conjugate` is not defined for `AbstractThunk`. Call `unthunk` first."))
 
+Base.real(x::AbstractThunk) = real(x())
+
 #####
 ##### `Thunk`
 #####

test/differentials.jl

@@ -102,7 +102,6 @@
                 @test refine_differential(typeof(1.0 + 1im), g) === g
                 @test refine_differential(typeof([1.0 + 1im]), g) === g
 
-                c isa Thunk && continue
                 @test refine_differential(typeof(1.2), g) == real(c)
                 @test refine_differential(typeof([1.2]), g) == real(c)
             end