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From: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Tue, 7 Apr 2020 11:29:56 +0000
Message-ID: <CAH6eHdS+DEpQU1nPN70hZte34_x8iWHotcOU6jWYeGqzB7UNVg@mail.gmail.com>
Subject: Re: [PATCH] Check DECL_CONTEXT of new/delete operators.
To: Nathan Sidwell <nathan@acm.org>
Cc: =?UTF-8?Q?Martin_Li=C5=A1ka?= <mliska@suse.cz>, 
 Jan Hubicka <hubicka@ucw.cz>, Richard Biener <richard.guenther@gmail.com>, 
 GCC Patches <gcc-patches@gcc.gnu.org>, Marc Glisse <marc.glisse@inria.fr>, 
 Jason Merrill <jason@redhat.com>
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On Mon, 6 Apr 2020 at 13:45, Nathan Sidwell wrote:
> The both operator new and operator delete are looked up in the same
> manner.  The std does not require a 'matching pair' be found.  but it is
> extremely poor form for a class to declare exactly one of operator
> {new,delete}.

There are unfortunately several such example in the standard!

I wonder how much benefit we will really get from trying to make this
optimisation too general.

Just eliding (or coalescing) implicit calls to ::operator new(size_t)
and ::operator delete(void*, size_t) (and the [] and align_val_t forms
of those) probably covers 99% of real cases.