On 5/22/18 9:48 PM, Manu wrote:
On 22 May 2018 at 06:44, Steven Schveighoffer via Digitalmars-d
<[email protected]> wrote:
On 5/22/18 1:01 AM, Manu wrote:
Ah! Dangling pointers... that might conservatively retain garbage.
That's a good reason.
Well, I was thinking more along the lines of accessing memory that is no
longer valid :) A destructor can, for instance, free C malloced memory.
The memory post-destruction is invalid... nobody will access it.
Accessing it should be undefined behaviour until such a time as the
memory is re-constructed with a new instance...
This particular sub-thread was about using destroy on something, not
freeing the memory. The memory is not invalid.
To clarify, I'm talking about something like this:
struct S
{
int *foo;
this(int x) { foo = cast(int*)malloc(int.sizeof); }
~this() { free(foo); }
}
auto s = S(1);
destroy(s);
*s.foo = 5; // oops
If s.foo is reset to null, then you get a nice predictable segfault. If
not, then you get memory corruption. Sure you can just say "undefined
behavior", but I'd rather the defined behavior.
-Steve
