From 107d9daa8f273827af8064d8878707b73464139a Mon Sep 17 00:00:00 2001
From: Mike J Innes <mike.j.innes@gmail.com>
Date: Fri, 1 Sep 2017 23:33:05 -0400
Subject: [PATCH] add some non-differentiable functions

---
 src/tracker/lib.jl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/tracker/lib.jl b/src/tracker/lib.jl
index a173ccac..37181bab 100644
--- a/src/tracker/lib.jl
+++ b/src/tracker/lib.jl
@@ -27,6 +27,9 @@ Base.sum(xs::TrackedScalar, dim...) = xs
 
 back!(::typeof(sum), Δ, xs::TrackedArray, dim...) = back!(xs, similar(xs.x) .= Δ)
 
+Base.maximum(xs::TrackedArray, args...) = maximum(xs.x, args...)
+Base.findfirst(xs::TrackedArray, args...) = findfirst(xs.x, args...)
+
 # BLAS
 
 a::TrackedMatrix * b::TrackedMatrix  = TrackedArray(Call(*, a, b))