On Wed, Jun 19, 2019 at 8:58 AM Bjarne Stroustrup <bjarne@stroustrup.com> wrote:

But, can somebody elaborate on the following, please :
AFAIK, we get the ability to use auto as function parameters:
foo(auto x)
Do we also allow to use concepts here:
foo(myconcept x)
If not I bet we will get it later.

HERE I really would like to be able to see that a standard concept is used
So
foo(myconcept x)
and
foo (string x)
should be able to be seen different.

Why?

I think that's a mistake. I used to subscribed to it and experimented with quite a few ways of distinguishing concepts, but found that they didn't seem to do anything useful. They were just uglier and more distracting than type names. Then I experimented with students *not* using distinguishing naming styles and found no problems. None. I'm reporting on a couple of years' thinking and experimentation here.


And don't forget CTAD.

std::vector<int> x = f();
std:: vector y = f();
std:: Container auto z = f();
or
std:: container z = f(); // some day?

The lines between type/template/concept are blurring, and - other than && - it isn't a big problem.

--
Be seeing you,
Tony