From abde997074c24580a92e531d7b38993f019520d3 Mon Sep 17 00:00:00 2001
From: Michael Abbott <32575566+mcabbott@users.noreply.github.com>
Date: Wed, 18 Aug 2021 23:09:10 -0400
Subject: [PATCH] accept Tuple Tangent for arrays

---
 src/projection.jl | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/projection.jl b/src/projection.jl
index 7be03e60c..a01774522 100644
--- a/src/projection.jl
+++ b/src/projection.jl
@@ -241,6 +241,12 @@ function (project::ProjectTo{AbstractArray})(dx::Number) # ... so we restore fro
     return fill(project.element(dx))
 end
 
+# Accept the Tangent corresponding to a Tuple -- Zygote's splats produce these
+function (project::ProjectTo{AbstractArray})(dx::Tangent{<:Any, <:Tuple})
+    dy = reshape(collect(backing(dx)), project.axes)
+    return project(dy)
+end
+
 # Ref -- works like a zero-array, also allows restoration from a number:
 ProjectTo(x::Ref) = ProjectTo{Ref}(; x=ProjectTo(x[]))
 (project::ProjectTo{Ref})(dx::Ref) = Ref(project.x(dx[]))