On Saturday, 5 December 2015 at 00:33:15 UTC, Vladimir Panteleev
wrote:
On Friday, 4 December 2015 at 23:38:08 UTC, deadalnix wrote:
On Friday, 4 December 2015 at 10:31:19 UTC, Vladimir Panteleev
wrote:
I realized this was off after posting but I don't understand
your reasoning either. The size and alignment just put a
bound on the number of bits, but without verification in the
setter you can't be sure, right?
If one of the bit within the alignment is not 0, that mean you
did something unsafe previously to create that pointer.
But this only applies to ... pointers to pointers, right? In D,
only pointer variables have to be aligned to maintain safety,
and even then that only applies to GC pointers (a C function
may return an "unaligned" pointer pointer). struct { align(1):
ubyte a; int b; } is still quite safe, and so is interpreting a
pointer into an array of ubytes as an uint.
No a pointer has some alignment that depends on whatever data it
points to. You cannot steal any bits for a char* (and
taggedPointer will reject it) you can steal one bit from a
short*, and so on. This is checked statically.
