From 1c3a63c42fdf8317a133a40ff3389b2ddadcc5c1 Mon Sep 17 00:00:00 2001
From: Mike Innes <mike.j.innes@gmail.com>
Date: Mon, 28 Jan 2019 10:11:07 +0000
Subject: [PATCH] fixes #574

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

diff --git a/src/tracker/lib/real.jl b/src/tracker/lib/real.jl
index a4f90a0c..0d8b3f43 100644
--- a/src/tracker/lib/real.jl
+++ b/src/tracker/lib/real.jl
@@ -39,6 +39,8 @@ Base.convert(::Type{TrackedReal{T}}, x::Real) where T = TrackedReal(convert(T, x
 Base.convert(::Type{TrackedReal{T}}, x::TrackedReal{S}) where {T,S} =
   error("Not implemented: convert tracked $S to tracked $T")
 
+(T::Type{<:TrackedReal})(x::Real) = convert(T, x)
+
 for op in [:(==), :≈, :<, :(<=)]
   @eval Base.$op(x::TrackedReal, y::Real) = Base.$op(data(x), y)
   @eval Base.$op(x::Real, y::TrackedReal) = Base.$op(x, data(y))