Re: is this a dirty struct?

From:
Dizzy <dizzy@roedu.net>
Newsgroups:
comp.lang.c++.moderated
Date:
Wed, 30 May 2007 14:41:46 CST
Message-ID:
<f3jo4j$kem$1@aioe.org>
Some more questions (sorry for not asking these in my first reply)

Branimir Maksimovic wrote:
....

void deallocate(const void* p)


Uhmm why receive const void* instead of void*? (std::free() and delete
require pointers to non-const, then you won't need the const_cast below).

{
void *c = const_cast<void*>(p);
Pool* d = static_cast<Pool*>(c);
d->next = next;
next = d;
}
// you need these two, too, as allocate just returns uninitialized
// block, and also addresses returned by expression new and alloc
// may differ


Hmm I must have missed this from the standard. But if it is so then the
value returned by "new" expression being different than the one by
allocate() will create problems later when deallocate() will be called with
the value of what "new" returned instead of the original allocate()
returned value.

static T* construct(void* p)
{
return new(p) T();
}


--
Dizzy

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