From bb33f3955a12b5173fee6f740338ec639e6d4a3e Mon Sep 17 00:00:00 2001
From: Klaus Crusius <klaus.crusius@web.de>
Date: Thu, 7 Jan 2021 12:03:42 +0100
Subject: [PATCH 1/2] fix ArrayInterface.ismutable(::ArrayPartition)

---
 .gitignore              | 1 +
 src/array_partition.jl  | 5 +++++
 test/partitions_test.jl | 6 +++++-
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 3f02ca74..49a815a8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.jl.*.cov
 *.jl.mem
 Manifest.toml
+.vscode
diff --git a/src/array_partition.jl b/src/array_partition.jl
index 45043081..688c567b 100644
--- a/src/array_partition.jl
+++ b/src/array_partition.jl
@@ -70,6 +70,11 @@ end
 # ignore dims since array partitions are vectors
 Base.ones(A::ArrayPartition, dims::NTuple{N,Int}) where {N} = ones(A)
 
+# mutable iff all components of ArrayPartition are mutable
+function ArrayInterface.ismutable(::Type{<:ArrayPartition{T,S}}) where {T,S}
+    all(ArrayInterface.ismutable, S.parameters)
+end
+
 ## vector space operations
 
 for op in (:+, :-)
diff --git a/test/partitions_test.jl b/test/partitions_test.jl
index 89f4a198..0b5f9b9b 100644
--- a/test/partitions_test.jl
+++ b/test/partitions_test.jl
@@ -1,4 +1,4 @@
-using RecursiveArrayTools, Test, Statistics
+using RecursiveArrayTools, Test, Statistics, ArrayInterface
 A = (rand(5),rand(5))
 p = ArrayPartition(A)
 @test (p.x[1][1],p.x[2][1]) == (p[1],p[6])
@@ -135,3 +135,7 @@ function foo(y, x)
 end
 foo(xcde0, xce0)
 #@test 0 == @allocated foo(xcde0, xce0)
+
+@testset "ArrayInterface.ismutable(ArrayPartition($a, $b)) == $r" for (a, b, r) in ((1,2, false), ([1], 2, false), ([1], [2], true))
+    @test ArrayInterface.ismutable(ArrayPartition(a, b)) == r
+end

From 3402cb5c6fda5f78924787aa2e1238148b57e515 Mon Sep 17 00:00:00 2001
From: Klaus Crusius <klaus.crusius@web.de>
Date: Fri, 8 Jan 2021 11:08:35 +0100
Subject: [PATCH 2/2] ismutable as generated function

---
 src/array_partition.jl | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/array_partition.jl b/src/array_partition.jl
index 688c567b..a2db9a0a 100644
--- a/src/array_partition.jl
+++ b/src/array_partition.jl
@@ -71,8 +71,9 @@ end
 Base.ones(A::ArrayPartition, dims::NTuple{N,Int}) where {N} = ones(A)
 
 # mutable iff all components of ArrayPartition are mutable
-function ArrayInterface.ismutable(::Type{<:ArrayPartition{T,S}}) where {T,S}
-    all(ArrayInterface.ismutable, S.parameters)
+@generated function ArrayInterface.ismutable(::Type{<:ArrayPartition{T,S}}) where {T,S}
+    res = all(ArrayInterface.ismutable, S.parameters)
+    return :( $res )
 end
 
 ## vector space operations