add Compat

Author: mcabbott

Project.toml

@@ -6,6 +6,7 @@ version = "0.6.20"
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
 ChainRules = "082447d4-558c-5d27-93f4-14fc19e9eca2"
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
+Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
 DiffRules = "b552c78f-8df3-52c6-915a-8e097449b14b"
 Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"
@@ -26,6 +27,7 @@ AbstractFFTs = "0.5, 1.0"
 ChainRules = "1.5"
 ChainRulesCore = "1.3"
 ChainRulesTestUtils = "1"
+Compat = "2.2, 3"
 DiffRules = "1.0"
 FillArrays = "0.8, 0.9, 0.10, 0.11, 0.12"
 ForwardDiff = "0.10"

src/Zygote.jl

@@ -11,6 +11,7 @@ using ChainRules: ChainRules, rrule, unthunk, canonicalize
 using IRTools
 using MacroTools, Requires
 using MacroTools: @forward
+using Compat  # for Julia 1.3, need Compat 2.2
 
 import Distributed: pmap, CachingPool, workers
 export Params, withgradient, gradient, withjacobian, jacobian, hessian, diaghessian, pullback, pushforward, @code_adjoint