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From: Michael S <already5chosen@yahoo.com>
Newsgroups: comp.lang.c
Subject: Re: constexpr keyword is unnecessary
Date: Sun, 13 Oct 2024 16:29:01 +0300
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On Sun, 13 Oct 2024 10:10:19 -0300
Thiago Adams <thiago.adams@gmail.com> wrote:

> Em 10/13/2024 10:06 AM, Michael S escreveu:
> > On Sun, 13 Oct 2024 09:38:04 -0300
> > Thiago Adams <thiago.adams@gmail.com> wrote:
> >   
> >> Em 10/13/2024 8:49 AM, Bonita Montero escreveu:  
> >>> Am 13.10.2024 um 13:37 schrieb Thiago Adams:
> >>>      
> >>>> Yes.
> >>>> constexpr is like - "require the initializer to be a constant
> >>>> expression." But the compiler will have to check it anyway.  
> >>>
> >>> I cannot understand why you are so militantly against this
> >>> new language feature that can be understood in 10 seconds.
> >>>      
> >>
> >> I have seen code like this:
> >>
> >> void func()
> >> {
> >>      constexpr int c = 1;
> >>      f(c);
> >> }
> >>
> >> For some reason, people believe that adding constexpr will
> >> magically improve optimization. In reality, it doesn't change
> >> anything compared to const and often reflects a misunderstanding
> >> of how the compiler works. As a result, I end up having to explain
> >> it. In this sense, constexpr is viral and spreads confusion.
> >>  
> > 
> > I see constexpr primarily as a way to enable use of functions from
> > math.h in static initializers.
> >   
> 
> Maybe you are thinking in C++? C does not have compile time functions.
> 

I'd expect that in the next standard a wide subset of math functions
would be allowed in constexp.
In C++ they become constexpr in C++23. If no unexpected difficulties
shows up in C++ then C would be next.