fix the build

src/compiler/shape.jl

@@ -46,5 +46,3 @@ end
 
 # TODO: make correct
 infer(::typeof(+), a, b) = a
-infer(::typeof(softmax), x) = x
-infer(::typeof(σ), x) = x

src/layers/activation.jl

@@ -13,3 +13,6 @@ softmax(xs) = exp.(xs) ./ sum(exp.(xs))
 flatten(xs) = reshape(xs, length(xs))
 
 shape(::typeof(flatten), in) = prod(in)
+
+infer(::typeof(softmax), x) = x
+infer(::typeof(σ), x) = x