Make QMetaTypeInterface constexpr on Windows

This was so far problematic as it gave various link errors. The solution
to that seems to be to make the default constructor of QPairVariantInterfaceImpl
constexpr to get around one set of problems.

The other problem to solve where undefined references to metaobjects. The
reason for that is apparently that QMetaTypeInterface contains a direct
pointer to the meta object, something the linker doesn't like. Adding a
level of indirection by using a function that returns the pointer seems
to solve that problem.

Fixes: QTBUG-88468
Change-Id: I5612ae807ea3b7e49bc40349d8d1fca1be9bd7ee
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

0 files changed, 0 insertions, 0 deletions