Expose QMetaTypeInterface::alignof in QMetaType

We already have the information in the QMetaTypeInterface, and provide
functions to access sizeof. Adding alignof support seems natural, and
should make it easier to handle over-aligned types.
This should also be helpful in QVariant.

Change-Id: I166be76f4b7d2d2e524a3a1e513bd2f361e887c1
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 23 insertions, 2 deletions

diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index ba3d788d53..1422e60a1c 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -500,7 +500,7 @@ int QMetaType::id() const
     This function is typically used together with construct()
     to perform low-level management of the memory used by a type.
 
-    \sa QMetaType::construct(), QMetaType::sizeOf()
+    \sa QMetaType::construct(), QMetaType::sizeOf(), QMetaType::alignOf()
 */
 int QMetaType::sizeOf() const
 {
@@ -510,6 +510,27 @@ int QMetaType::sizeOf() const
 }
 
 /*!
+  \fn int QMetaType::alignOf() const
+  \since 6.0
+
+  Returns the alignment of the type in bytes (i.e. alignof(T),
+  where T is the actual type for which this QMetaType instance
+  was constructed for).
+
+  This function is typically used together with construct()
+  to perform low-level management of the memory used by a type.
+
+  \sa QMetaType::construct(), QMetaType::sizeOf()
+
+ */
+int QMetaType::alignOf() const
+{
+    if (d_ptr)
+        return d_ptr->alignment;
+    return 0;
+}
+
+/*!
     \fn TypeFlags QMetaType::flags() const
     \since 5.0
 
@@ -1585,7 +1606,7 @@ void QMetaType::destruct(int type, void *where)
     This function is typically used together with construct()
     to perform low-level management of the memory used by a type.
 
-    \sa construct()
+    \sa construct(), QMetaType::alignOf()
 */
 int QMetaType::sizeOf(int type)
 {