Re: Implementing overloaded operator new[]/delete[]

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 24 Sep 2007 08:30:36 -0000

Message-ID:

<1190622636.984726.48030@n39g2000hsh.googlegroups.com>

On Sep 23, 11:56 pm, "Alf P. Steinbach" <al...@start.no> wrote:

[...]

No. Actually, apart from implementing your own per-class allocation
scheme, the main use of implementing your own allocator function that
I'm aware of is to obfuscate the new'ing of an instance of the class in
question, so that you're in practice ensured that only your own special
macro for that is used, which then guarantees that the pointer produced
is wrapped in a suitable smart pointer.

That doesn't work.

In principle I guess it could
also be used to disallow dynamic allocation, although I fail to imagine
any practical use for that.

The most frequent use is debugging. There's a debugging
new/delete at my site, for example, which saves the stack
walkback at the allocation site, sets guard zones at either end
(to detect overwrites), checks for double deletes and memory
leaks, etc. It's doubtlessly significantly slower than the
standard version, but I use it in my unit tests, and have found
a few bugs thanks to it.

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