Re: delete this??????
On Apr 4, 6:32 pm, Juha Nieminen <nos...@thanks.invalid> wrote:
Victor Bazarov wrote:
Nothing special about deleting 'this'. The lifetime of the object
ends when its destructor is invoked. What else do you expect it to
say?
That code after a "delete this;" is guaranteed to work correctly
as long as 'this' is not accessed (implicitly or explicitly).
I bet it doesn't say that, though, so if we want to ensure complete
compatibility, what should we assume?
Well, it certainly doesn't say that: if it did, I'd put all the
entire application in one function which did "delete this" at
the top, and never have to debug again:-).
But you're right to ask: an implementation might conceivably
store the return address in the object, or some silliness like
that. In fact, the standard does set up a set of very specific
rules. As long as you obey those rules, an implementation is
required to make your code work. Since there is nothing in the
rules which says you cannot "delete this", it is OK, as long as
you obey the rest of the rules. (One of those rules say, for
example, that you cannot even read the this pointer without
incurring undefined behavior. Also, you cannot access any
non-static member, including calling a non-static function,
since this involves reading the this pointer.)
The issue was discussed before the standard was adopted, and the
concensus was that "delete this" is legal. (There's even an
example where the code explicitly calls this->~C(). Not quite
"delete this", but most of the same issues apply.)
--
James Kanze (GABI Software) email:james.kanze@gmail.com
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