QStringRef: make nothrow move-assign- and -constructible

The move special members were inhibited by the presence
of a non-trivial copy constructor/assignment operator
and destructor. Restore them.

While we're at it, move all the special member functions
we should not have defined into an #if QT_VERSION block.

Change-Id: I873a99bfefe03e0fb02676e3431fd51f8c8f0adc
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 13 insertions, 9 deletions

diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 0038fba2c3..643378a7bd 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -1363,24 +1363,28 @@ public:
     inline QStringRef(const QString *string, int position, int size);
     inline QStringRef(const QString *string);
 
-    // ### Qt 6: remove this copy constructor, the implicit one is fine
-    inline QStringRef(const QStringRef &other)
+#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
+    // ### Qt 6: remove all of these, the implicit ones are fine
+    QStringRef(const QStringRef &other) Q_DECL_NOTHROW
         :m_string(other.m_string), m_position(other.m_position), m_size(other.m_size)
         {}
-
-    // ### Qt 6: remove this destructor, the implicit one is fine
+#ifdef Q_COMPILER_RVALUE_REFS
+    QStringRef(QStringRef &&other) Q_DECL_NOTHROW : m_string(other.m_string), m_position(other.m_position), m_size(other.m_size) {}
+    QStringRef &operator=(QStringRef &&other) Q_DECL_NOTHROW { return *this = other; }
+#endif
+    QStringRef &operator=(const QStringRef &other) Q_DECL_NOTHROW {
+        m_string = other.m_string; m_position = other.m_position;
+        m_size = other.m_size; return *this;
+    }
     inline ~QStringRef(){}
+#endif // Qt < 6.0.0
+
     inline const QString *string() const { return m_string; }
     inline int position() const { return m_position; }
     inline int size() const { return m_size; }
     inline int count() const { return m_size; }
     inline int length() const { return m_size; }
 
-    inline QStringRef &operator=(const QStringRef &other) {
-        m_string = other.m_string; m_position = other.m_position;
-        m_size = other.m_size; return *this;
-    }
-
     int indexOf(const QString &str, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     int indexOf(QChar ch, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;
     int indexOf(QLatin1String str, int from = 0, Qt::CaseSensitivity cs = Qt::CaseSensitive) const;