fixes #367

src/tracker/array.jl

@@ -48,7 +48,7 @@ back!(::TrackedArray) = error("Value is not scalar; use `back!(sum(x))` or `back
 
 # Fallthrough methods
 
-for f in :[Base.size, Base.ndims].args
+for f in :[Base.size, Base.ndims, Base.collect].args
   @eval @inline $f(x::TrackedArray, a...) = $f(data(x), a...)
 end
 

test/cuda/cuda.jl

@@ -26,6 +26,10 @@ x = [1,2,3]
 cx = gpu(x)
 @test Flux.crossentropy(x,x) ≈ Flux.crossentropy(cx,cx)
 
+xs = param(rand(5,5))
+ys = Flux.onehotbatch(1:5,1:5)
+@test collect(cu(xs) .+ cu(ys)) ≈ collect(xs .+ ys)
+
 c = gpu(Conv((2,2),3=>4))
 l = c(gpu(rand(10,10,3,2)))
 Flux.back!(sum(l))