From 735e2f787acf1f74c00e26730c7a477a7a59129f Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Mon, 13 Dec 2021 12:29:51 +0100
Subject: [PATCH] QRingBuffer: simplify QRingChunk special member functions
 [1/2]
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Let the compiler generate the copy and move SMFs.

Statically assert that the move SMFs are still noexcept.

Pick-to: 6.3
Change-Id: I1c569bdf893a5f2cda972c0dd8196cab62494fcb
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 src/corelib/tools/qringbuffer.cpp |  8 +++++++-
 src/corelib/tools/qringbuffer_p.h | 20 +-------------------
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/src/corelib/tools/qringbuffer.cpp b/src/corelib/tools/qringbuffer.cpp
index f32673b9bd7..b10362b0cdb 100644
--- a/src/corelib/tools/qringbuffer.cpp
+++ b/src/corelib/tools/qringbuffer.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Copyright (C) 2015 Alex Trotsenko <alex1973tr@gmail.com>
 ** Contact: https://www.qt.io/licensing/
 **
@@ -40,10 +40,16 @@
 
 #include "private/qringbuffer_p.h"
 #include "private/qbytearray_p.h"
+
+#include <type_traits>
+
 #include <string.h>
 
 QT_BEGIN_NAMESPACE
 
+static_assert(std::is_nothrow_move_constructible_v<QRingChunk>);
+static_assert(std::is_nothrow_move_assignable_v<QRingChunk>);
+
 void QRingChunk::allocate(qsizetype alloc)
 {
     Q_ASSERT(alloc > 0 && size() == 0);
diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index 1ab0053d1ac..84e0f9ddec5 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -69,10 +69,6 @@ public:
         headOffset(0), tailOffset(0)
     {
     }
-    inline QRingChunk(const QRingChunk &other) noexcept :
-        chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
-    {
-    }
     explicit inline QRingChunk(qsizetype alloc) :
         chunk(alloc, Qt::Uninitialized), headOffset(0), tailOffset(0)
     {
@@ -86,20 +82,6 @@ public:
     {
     }
 
-    inline QRingChunk &operator=(const QRingChunk &other) noexcept
-    {
-        chunk = other.chunk;
-        headOffset = other.headOffset;
-        tailOffset = other.tailOffset;
-        return *this;
-    }
-    inline QRingChunk(QRingChunk &&other) noexcept :
-        chunk(other.chunk), headOffset(other.headOffset), tailOffset(other.tailOffset)
-    {
-        other.headOffset = other.tailOffset = 0;
-    }
-    QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QRingChunk)
-
     inline void swap(QRingChunk &other) noexcept
     {
         chunk.swap(other.chunk);