From d162e028bbb6f50cfdb9cac0eadbdd7c41729d14 Mon Sep 17 00:00:00 2001
From: Mike J Innes <mike.j.innes@gmail.com>
Date: Wed, 23 Aug 2017 17:50:49 +0100
Subject: [PATCH] utility method

---
 src/tracker/Tracker.jl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/tracker/Tracker.jl b/src/tracker/Tracker.jl
index 38374e3d..f5684051 100644
--- a/src/tracker/Tracker.jl
+++ b/src/tracker/Tracker.jl
@@ -50,6 +50,8 @@ function back!(x::TrackedArray, Δ)
   back!(x.f, Δ)
 end
 
+back!(x::TrackedScalar) = back!(x, 1)
+
 macro back!(x, Δ)
   quote
     x = $(esc(x))