diff --git a/narrow-derive/tests/expand/struct/named/generic.expanded.rs b/narrow-derive/tests/expand/struct/named/generic.expanded.rs
index d90b08b..285b7d0 100644
--- a/narrow-derive/tests/expand/struct/named/generic.expanded.rs
+++ b/narrow-derive/tests/expand/struct/named/generic.expanded.rs
@@ -30,7 +30,11 @@ impl<'a, T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for Foo<
 where
     T: Copy,
 {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<'a, T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<'a, T, Buffer>;
 }
 struct FooArray<'a, T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType>
 where
diff --git a/narrow-derive/tests/expand/struct/named/generic_option.expanded.rs b/narrow-derive/tests/expand/struct/named/generic_option.expanded.rs
index 6a869d5..deb9cb0 100644
--- a/narrow-derive/tests/expand/struct/named/generic_option.expanded.rs
+++ b/narrow-derive/tests/expand/struct/named/generic_option.expanded.rs
@@ -19,7 +19,11 @@ for ::std::option::Option<Bar<T>> {
     > = narrow::array::StructArray<Bar<T>, true, Buffer>;
 }
 impl<T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for Bar<T> {
-    type Array<Buffer: narrow::buffer::BufferType> = BarArray<T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = BarArray<T, Buffer>;
 }
 struct BarArray<T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType> {
     a: <u32 as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/named/simple.expanded.rs b/narrow-derive/tests/expand/struct/named/simple.expanded.rs
index b71658f..b2fb7e0 100644
--- a/narrow-derive/tests/expand/struct/named/simple.expanded.rs
+++ b/narrow-derive/tests/expand/struct/named/simple.expanded.rs
@@ -18,7 +18,11 @@ impl narrow::array::ArrayType<Foo> for ::std::option::Option<Foo> {
     > = narrow::array::StructArray<Foo, true, Buffer>;
 }
 impl narrow::array::StructArrayType for Foo {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<Buffer>;
 }
 struct FooArray<Buffer: narrow::buffer::BufferType> {
     a: <u32 as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/unit/const_generic.expanded.rs b/narrow-derive/tests/expand/struct/unit/const_generic.expanded.rs
index 0f857a9..655eacc 100644
--- a/narrow-derive/tests/expand/struct/unit/const_generic.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unit/const_generic.expanded.rs
@@ -19,7 +19,11 @@ impl<const N: usize> narrow::array::ArrayType<Foo<N>> for ::std::option::Option<
     > = narrow::array::StructArray<Foo<N>, true, Buffer>;
 }
 impl<const N: usize> narrow::array::StructArrayType for Foo<N> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<N, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<N, Buffer>;
 }
 pub struct FooArray<const N: usize, Buffer: narrow::buffer::BufferType>(
     pub narrow::array::NullArray<Foo<N>, false, Buffer>,
diff --git a/narrow-derive/tests/expand/struct/unit/const_generic_default.expanded.rs b/narrow-derive/tests/expand/struct/unit/const_generic_default.expanded.rs
index 972f2f0..a9e699c 100644
--- a/narrow-derive/tests/expand/struct/unit/const_generic_default.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unit/const_generic_default.expanded.rs
@@ -19,7 +19,11 @@ impl<const N: usize> narrow::array::ArrayType<Foo<N>> for ::std::option::Option<
     > = narrow::array::StructArray<Foo<N>, true, Buffer>;
 }
 impl<const N: usize> narrow::array::StructArrayType for Foo<N> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<N, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<N, Buffer>;
 }
 pub struct FooArray<const N: usize, Buffer: narrow::buffer::BufferType>(
     pub narrow::array::NullArray<Foo<N>, false, Buffer>,
diff --git a/narrow-derive/tests/expand/struct/unit/self.expanded.rs b/narrow-derive/tests/expand/struct/unit/self.expanded.rs
index 61da210..f0bb5d3 100644
--- a/narrow-derive/tests/expand/struct/unit/self.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unit/self.expanded.rs
@@ -33,7 +33,11 @@ impl narrow::array::StructArrayType for Foo
 where
     Self: Debug,
 {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<Buffer>;
 }
 struct FooArray<Buffer: narrow::buffer::BufferType>(
     narrow::array::NullArray<Foo, false, Buffer>,
diff --git a/narrow-derive/tests/expand/struct/unit/simple.expanded.rs b/narrow-derive/tests/expand/struct/unit/simple.expanded.rs
index e34b02f..6853eef 100644
--- a/narrow-derive/tests/expand/struct/unit/simple.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unit/simple.expanded.rs
@@ -19,7 +19,11 @@ impl narrow::array::ArrayType<Foo> for ::std::option::Option<Foo> {
     > = narrow::array::StructArray<Foo, true, Buffer>;
 }
 impl narrow::array::StructArrayType for Foo {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<Buffer>;
 }
 struct FooArray<Buffer: narrow::buffer::BufferType>(
     narrow::array::NullArray<Foo, false, Buffer>,
diff --git a/narrow-derive/tests/expand/struct/unit/where_clause.expanded.rs b/narrow-derive/tests/expand/struct/unit/where_clause.expanded.rs
index 2dd37ca..d6d2917 100644
--- a/narrow-derive/tests/expand/struct/unit/where_clause.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unit/where_clause.expanded.rs
@@ -38,7 +38,11 @@ where
     Self: Sized,
     (): From<Self>,
 {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<N, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<N, Buffer>;
 }
 pub(super) struct FooArray<const N: bool, Buffer: narrow::buffer::BufferType>(
     pub(super) narrow::array::NullArray<Foo<N>, false, Buffer>,
diff --git a/narrow-derive/tests/expand/struct/unnamed/generic.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/generic.expanded.rs
index 18d3b4a..d43309e 100644
--- a/narrow-derive/tests/expand/struct/unnamed/generic.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/generic.expanded.rs
@@ -34,7 +34,11 @@ where
     Self: Sized,
     <T as Add<Self>>::Output: Debug,
 {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<'a, T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<'a, T, Buffer>;
 }
 struct FooArray<
     'a,
@@ -227,7 +231,11 @@ for ::std::option::Option<FooBar<T>> {
     > = narrow::array::StructArray<FooBar<T>, true, Buffer>;
 }
 impl<T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for FooBar<T> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooBarArray<T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooBarArray<T, Buffer>;
 }
 struct FooBarArray<T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType>(
     <T as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/unnamed/lifetime.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/lifetime.expanded.rs
index 45f9875..e3f89f2 100644
--- a/narrow-derive/tests/expand/struct/unnamed/lifetime.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/lifetime.expanded.rs
@@ -16,7 +16,11 @@ for ::std::option::Option<Foo<'a, T>> {
     > = narrow::array::StructArray<Foo<'a, T>, true, Buffer>;
 }
 impl<'a, T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for Foo<'a, T> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<'a, T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<'a, T, Buffer>;
 }
 struct FooArray<'a, T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType>(
     <&'a T as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/unnamed/multiple.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/multiple.expanded.rs
index 702782c..254575c 100644
--- a/narrow-derive/tests/expand/struct/unnamed/multiple.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/multiple.expanded.rs
@@ -14,7 +14,11 @@ impl narrow::array::ArrayType<Bar> for ::std::option::Option<Bar> {
     > = narrow::array::StructArray<Bar, true, Buffer>;
 }
 impl narrow::array::StructArrayType for Bar {
-    type Array<Buffer: narrow::buffer::BufferType> = BarArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = BarArray<Buffer>;
 }
 struct BarArray<Buffer: narrow::buffer::BufferType>(
     <u8 as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/unnamed/nested.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/nested.expanded.rs
index 4e7d468..2f94861 100644
--- a/narrow-derive/tests/expand/struct/unnamed/nested.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/nested.expanded.rs
@@ -14,7 +14,11 @@ impl narrow::array::ArrayType<Foo> for ::std::option::Option<Foo> {
     > = narrow::array::StructArray<Foo, true, Buffer>;
 }
 impl narrow::array::StructArrayType for Foo {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<Buffer>;
 }
 struct FooArray<Buffer: narrow::buffer::BufferType>(
     <u32 as narrow::array::ArrayType<
@@ -152,7 +156,11 @@ impl narrow::array::ArrayType<Bar> for ::std::option::Option<Bar> {
     > = narrow::array::StructArray<Bar, true, Buffer>;
 }
 impl narrow::array::StructArrayType for Bar {
-    type Array<Buffer: narrow::buffer::BufferType> = BarArray<Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = BarArray<Buffer>;
 }
 struct BarArray<Buffer: narrow::buffer::BufferType>(
     <Foo as narrow::array::ArrayType<
diff --git a/narrow-derive/tests/expand/struct/unnamed/nested_generic.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/nested_generic.expanded.rs
index dd3a08e..e680d39 100644
--- a/narrow-derive/tests/expand/struct/unnamed/nested_generic.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/nested_generic.expanded.rs
@@ -28,7 +28,11 @@ impl<T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for Foo<T>
 where
     T: Copy,
 {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<T, Buffer>;
 }
 struct FooArray<T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType>(
     <T as narrow::array::ArrayType<
@@ -196,7 +200,11 @@ for ::std::option::Option<Bar<'a, T>> {
     > = narrow::array::StructArray<Bar<'a, T>, true, Buffer>;
 }
 impl<'a, T: narrow::array::ArrayType<T>> narrow::array::StructArrayType for Bar<'a, T> {
-    type Array<Buffer: narrow::buffer::BufferType> = BarArray<'a, T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = BarArray<'a, T, Buffer>;
 }
 struct BarArray<'a, T: narrow::array::ArrayType<T>, Buffer: narrow::buffer::BufferType>(
     <&'a Foo<
@@ -385,7 +393,11 @@ impl<'a> narrow::array::ArrayType<FooBar<'a>> for ::std::option::Option<FooBar<'
     > = narrow::array::StructArray<FooBar<'a>, true, Buffer>;
 }
 impl<'a> narrow::array::StructArrayType for FooBar<'a> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooBarArray<'a, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooBarArray<'a, Buffer>;
 }
 struct FooBarArray<'a, Buffer: narrow::buffer::BufferType>(
     <Bar<
diff --git a/narrow-derive/tests/expand/struct/unnamed/simple.expanded.rs b/narrow-derive/tests/expand/struct/unnamed/simple.expanded.rs
index 49d8888..0166eca 100644
--- a/narrow-derive/tests/expand/struct/unnamed/simple.expanded.rs
+++ b/narrow-derive/tests/expand/struct/unnamed/simple.expanded.rs
@@ -16,7 +16,11 @@ for ::std::option::Option<Foo<T>> {
     > = narrow::array::StructArray<Foo<T>, true, Buffer>;
 }
 impl<T: Sized + narrow::array::ArrayType<T>> narrow::array::StructArrayType for Foo<T> {
-    type Array<Buffer: narrow::buffer::BufferType> = FooArray<T, Buffer>;
+    type Array<
+        Buffer: narrow::buffer::BufferType,
+        OffsetItem: narrow::offset::OffsetElement,
+        UnionLayout: narrow::array::union::UnionType,
+    > = FooArray<T, Buffer>;
 }
 struct FooArray<
     T: Sized + narrow::array::ArrayType<T>,