From 56b82b1b7f0212cf0ceaee4dc010d605adef80f3 Mon Sep 17 00:00:00 2001
From: Karoy Lorentey <klorentey@apple.com>
Date: Mon, 30 Aug 2021 13:25:58 -0700
Subject: [PATCH] Freeze some types for consistency with their inlinable
 initializers

Note: @frozen does *not* mean that we actually consider these struct types frozen. Their layout may arbitrarily change between even minor releases.
---
 Sources/DequeModule/Deque+Collection.swift                      | 1 +
 Sources/DequeModule/Deque._Storage.swift                        | 1 +
 Sources/DequeModule/Deque._UnsafeHandle.swift                   | 1 +
 Sources/DequeModule/_DequeBuffer.swift                          | 1 +
 Sources/DequeModule/_UnsafeWrappedBuffer.swift                  | 2 ++
 .../OrderedSet/OrderedSet+UnorderedView.swift                   | 1 +
 6 files changed, 7 insertions(+)

diff --git a/Sources/DequeModule/Deque+Collection.swift b/Sources/DequeModule/Deque+Collection.swift
index d88846626..e1614b6a5 100644
--- a/Sources/DequeModule/Deque+Collection.swift
+++ b/Sources/DequeModule/Deque+Collection.swift
@@ -16,6 +16,7 @@ extension Deque: Sequence {
   // conversions from indices to storage slots.
 
   /// An iterator over the members of a deque.
+  @frozen
   public struct Iterator: IteratorProtocol {
     @usableFromInline
     internal var _storage: Deque._Storage
diff --git a/Sources/DequeModule/Deque._Storage.swift b/Sources/DequeModule/Deque._Storage.swift
index 6e7de6d7c..2c0a5d330 100644
--- a/Sources/DequeModule/Deque._Storage.swift
+++ b/Sources/DequeModule/Deque._Storage.swift
@@ -10,6 +10,7 @@
 //===----------------------------------------------------------------------===//
 
 extension Deque {
+  @frozen
   @usableFromInline
   struct _Storage {
     @usableFromInline
diff --git a/Sources/DequeModule/Deque._UnsafeHandle.swift b/Sources/DequeModule/Deque._UnsafeHandle.swift
index b802821e3..ed32110d3 100644
--- a/Sources/DequeModule/Deque._UnsafeHandle.swift
+++ b/Sources/DequeModule/Deque._UnsafeHandle.swift
@@ -10,6 +10,7 @@
 //===----------------------------------------------------------------------===//
 
 extension Deque {
+  @frozen
   @usableFromInline
   internal struct _UnsafeHandle {
     @usableFromInline
diff --git a/Sources/DequeModule/_DequeBuffer.swift b/Sources/DequeModule/_DequeBuffer.swift
index 62fd9e214..bc0df278a 100644
--- a/Sources/DequeModule/_DequeBuffer.swift
+++ b/Sources/DequeModule/_DequeBuffer.swift
@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+@_fixed_layout
 @usableFromInline
 internal class _DequeBuffer<Element>: ManagedBuffer<_DequeBufferHeader, Element> {
   @inlinable
diff --git a/Sources/DequeModule/_UnsafeWrappedBuffer.swift b/Sources/DequeModule/_UnsafeWrappedBuffer.swift
index 0424403e6..06a0a580c 100644
--- a/Sources/DequeModule/_UnsafeWrappedBuffer.swift
+++ b/Sources/DequeModule/_UnsafeWrappedBuffer.swift
@@ -9,6 +9,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+@frozen
 @usableFromInline
 internal struct _UnsafeWrappedBuffer<Element> {
   @usableFromInline
@@ -51,6 +52,7 @@ internal struct _UnsafeWrappedBuffer<Element> {
   internal var count: Int { first.count + (second?.count ?? 0) }
 }
 
+@frozen
 @usableFromInline
 internal struct _UnsafeMutableWrappedBuffer<Element> {
   @usableFromInline
diff --git a/Sources/OrderedCollections/OrderedSet/OrderedSet+UnorderedView.swift b/Sources/OrderedCollections/OrderedSet/OrderedSet+UnorderedView.swift
index cc679d43d..b0222a64c 100644
--- a/Sources/OrderedCollections/OrderedSet/OrderedSet+UnorderedView.swift
+++ b/Sources/OrderedCollections/OrderedSet/OrderedSet+UnorderedView.swift
@@ -12,6 +12,7 @@
 extension OrderedSet {
   /// An unordered view into an ordered set, providing `SetAlgebra`
   /// conformance.
+  @frozen
   public struct UnorderedView {
     public typealias Element = OrderedSet.Element