On Tue, Apr 7, 2020 at 1:30 PM Jonathan Wakely <jwakely....@gmail.com> wrote:
>
> 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.
IIRC the only reason to have the optimization was to fully elide
STL containers when possible. That brings in allocators and
thus non ::new/::delete allocations. Which then suggests that
our standard library implementation could annotate allocation
points somehow.
Richard.
