On Wed, 2025-07-16 at 21:32 +0200, Marcin Jaczewski wrote:
> śr., 16 lip 2025 o 11:04 Avi Kivity via Std-Proposals
> <std-proposals_at_[hidden]> napisał(a):
> >
> > On Wed, 2025-07-16 at 02:14 -0400, Jason McKesson via Std-Proposals
> > wrote:
> >
> > On Tue, Jul 15, 2025 at 9:59 AM Jan Schultke via Std-Proposals
> > <std-proposals_at_[hidden]> wrote:
> >
> >
> > I recall discussing this with other people at some point; not sure
> > if
> > there's already an existing proposal for it.
> >
> > I think it's well-motivated; we have function objects for
> > std::plus/+
> > and other sort of builtin things that you cannot (always) for a
> > function pointer to, and this fits right in with those.
> >
> > However, std::construct is a bad name. You're basically making a
> > callable type in the style of std::plus and std::less; all of those
> > are named using a noun, presumably because they are not functions.
> > std::construct sounds dangerously close to std::construct_at;
> > there's
> > some potential for confusion.
> >
> > Something like std::construction or std::constructor would be more
> > fitting for that type.
> >
> >
> > On the bikeshedding point,
> >
> >
> > I'll be happy with any name provided it's standardized, but I
> > cannot resist a naming argument.
> >
> >
> > `std::construct` sounds like it should be
> > related to `std::construct_at`, but it very much isn't.
> >
> >
> >
> > Why not? std::construct<T>(x, y) constructs a T from an x and a y.
> > std::construct_at<T>(location, x, y) constructs a T from an x and a
> > y at the given location.
> >
>
> Could a better name be: `make_value<T>`? it will be similar to other
> `make_*` functions and explicitly say what it does.


If we change it to be a class template (as suggested in the other
branch of the thread), so the way to use it is:

  auto whatever = std::make_value<T>();
  auto v = whatever(args);

then it looks odd as make_value<T>() didn't make a value, but made a a
value constructor. So I plan to rename it to std::constructor. Then an
object of that type is a make_value-er


  auto make_value = std::constructor<T>();
  auto v = make_value(args);

>
> >
> > You're getting
> > a callable that represents the object's constructor, so
> > `std::constructor` fits right alongside `std::function` and
> > `std::mem_fn`.
> >
> >
> >
> > I also agree with that. And given that std::construct<T> is likely
> > to be used on its own and not immediately be called, perhaps more
> > weight should be given to that use case.
> > --
> > Std-Proposals mailing list
> > Std-Proposals_at_[hidden]
> > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals