On 1/27/16 5:35 PM, Igor wrote:
On Wednesday, 27 January 2016 at 14:31:20 UTC, Steven Schveighoffer wrote:
All D destructors should destroy all the members. And generally
speaking, if you ever plan to use a class with the GC, you should only
destroy non-GC members. The GC members may already be destroyed.
BTW, I wrote that wrong, I should have said "All D destructors *should
do is* destroy all the members." In other words, you shouldn't do
anything but destroy members.
There needs to be better docs on this? Or at least someone needs to
provide a link! ;)
http://dlang.org/spec/class.html#destructors
"Furthermore, the order in which the garbage collector calls destructors
for unreference objects is not specified. This means that when the
garbage collector calls a destructor for an object of a class that has
members that are references to garbage collected objects, those
references may no longer be valid. **This means that destructors cannot
reference sub objects.**"
(emphasis mine)
Why can there be an "deplace" equivalent to emplace?
emplace is not responsible for allocation, it just does all the
necessary things to place an object inside memory you provide (wherever
it came from), and call the proper constructor.
The opposite of emplace is destroy. This calls the destructor and resets
the class to a "destroyed" state (so calling destroy on a class a second
time will not call the destructor again).
Everone says it's so easy not to use the GC in D yet I can't seem to
find any real world examples ;/
The easiness of doing it is a judgment call. However, it is possible.
I'm sure there are examples out there, but I'm not well versed in where
to find them.
-Steve
