Add an extra check for qssize_t's size and type

The definitions of size_t and ptrdiff_t ([support.types.layout] p2 and
p3 respectively) do not specify that they need to be as big as a
pointer. They just need to be big enough to hold the size of the largest
object and the biggest array subscript, respectively, the platform
supports (e.g., 16-bit DOS would have them as 16-bit in all memory
models, except huge).

But we depend on them actually being the size of a pointer in many
places, such as in QArrayData::offset, that stores the linear distance
from the end of the structure to the beginning of the data, wherever it
is in memory.

It's also a good idea to verify that qptrdiff and qssize_t are the same
type.

Change-Id: I9ad33fff8b634979bdbafffd14bbd1223afc58e8
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

0 files changed, 0 insertions, 0 deletions