Re: Using malloc in C++

From:

red floyd <redfloyd@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 30 Jun 2010 09:03:51 -0700 (PDT)

Message-ID:

<5ca6f086-7b74-4472-a7ed-c15745c049ac@j8g2000yqd.googlegroups.com>

On Jun 30, 3:09 am, Stuart Golodetz
<sgolod...@NdOiSaPlA.pMiPpLeExA.ScEom> wrote:

red floyd wrote:

On Jun 29, 11:55 am, Bharath <bharath...@gmail.com> wrote:

On Jun 28, 5:31 pm, Stuart Golodetz <b...@blah.com> wrote:

[placement new example redacted]

Wow Stu, that clears up the confusion. I had an idea that I had to use
the new operator to call the constructor again, but wasn't sure how.

Bharath,

I'm guessing you're just learning the language.

Stu's example works, but DO NOT WRITE CODE LIKE THAT!!!! It's a
workaround
if you *must* use malloc/free because of legacy code. If at all
possible,
don't use malloc/free, but instead use new/delete. New has the
following
advantages:

* Will automatically construct the object
* Will never return NULL, but will instead throw std::bad_alloc
* No cast from void* is required.

Similarly, delete will automatically destruct objects allocated by
new.

There are occasionally valid reasons to do this sort of thing (I seem to
recall the Phoenix singleton implementation used this), but you're right
that it's one to avoid in most situations.

Oh definitely. But the OP looks like a newbie, and I doubt he's
working with
Phoenix singletons.