QMatrix, QTransform: restore nothrow move special members

The user-defined copy assignment and (on QMatrix) copy
constructors inhibit the move special member functions.

We cannot do something about it in Qt 5, because these
classes are exported (which they shouldn't be), and
because making them trivially copyable might change
how they are passed to functions by value, so we need
to supply all the missing member functions manually.

Change-Id: I59e480d7ba02cac7e3d654cb3345f541e0701f4c
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/src/gui/painting/qmatrix.h b/src/gui/painting/qmatrix.h
index 342898b561..b28c8433cd 100644
--- a/src/gui/painting/qmatrix.h
+++ b/src/gui/painting/qmatrix.h
@@ -60,7 +60,16 @@ public:
     QMatrix();
     QMatrix(qreal m11, qreal m12, qreal m21, qreal m22,
             qreal dx, qreal dy);
-    QMatrix(const QMatrix &matrix);
+
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    // ### Qt 6: remove; the compiler-generated ones are fine!
+    QMatrix &operator=(QMatrix &&other) Q_DECL_NOTHROW // = default
+    { memcpy(this, &other, sizeof(QMatrix)); return *this; }
+    QMatrix &operator=(const QMatrix &) Q_DECL_NOTHROW; // = default
+    QMatrix(QMatrix &&other) Q_DECL_NOTHROW // = default
+    { memcpy(this, &other, sizeof(QMatrix)); }
+    QMatrix(const QMatrix &other) Q_DECL_NOTHROW; // = default
+#endif
 
     void setMatrix(qreal m11, qreal m12, qreal m21, qreal m22,
                    qreal dx, qreal dy);
@@ -106,8 +115,6 @@ public:
     QMatrix &operator*=(const QMatrix &);
     QMatrix operator*(const QMatrix &o) const;
 
-    QMatrix &operator=(const QMatrix &);
-
     operator QVariant() const;
 
 private: