On Monday, 15 June 2015 at 12:08:31 UTC, Dmitry Olshansky wrote:
On 13-Jun-2015 14:32, rsw0x wrote:
http://dlang.org/garbage.html
Do not take advantage of alignment of pointers to store bit
flags in the
low order bits:
p = cast(void*)(cast(int)p | 1); // error: undefined behavior
if this restriction is actually imposed - why does
std.bitmanip.tagged{ClassRef,Pointer} even exist?
AFAIK the restriction was that pointers _themselves_ have to be
stored at word-aligned addresses. This allows GC to scan memory
cheaper w/o considering if some misaligned address may contain
a pointer.
this doesn't make any sense, it's referring to an object p (of
void*), not the location of p. It's setting the lsb of p to 1 and
claiming it's undefined behavior, when it's clearly not.
Unless I misunderstand it.
