Re: is_constant_evaluated

From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2021-08-05 00:53:02

On 8/5/21 2:14 AM, Gavin Lambert via Boost wrote:
> On 5/08/2021 7:03 am, Andrey Semashev wrote:
>> I might add that including <type_traits> just to test got a feature 
>> macro is not good.
> 
> It wouldn't be good in something like Boost.Config, no.
> 
> But if you're doing that check at actual point of use then you've almost 
> certainly already included <type_traits> anyway, so it's "free".

No, not really. Not only because needing is_constant_evaluated does not 
equate to needing type traits or metaprogramming, but because if the 
macro check says "no" then you've included <type_traits> for nothing.