Subject: Re: [boost] traits classes vs. metafunctions
From: Stefan Strasser (strasser_at_[hidden])
Date: 2013-03-31 13:57:05
Am 31.03.2013 19:46, schrieb Jonathan Wakely:
> On 31 March 2013 18:31, Stefan Strasser wrote:
>>
>> I don't understand why they didn't get rid of the "metafunction" concept as
>> we use it today entirely, but introduce it into the official standard via
>> type traits.
>> E.g. via a "constexpr" that can return types, or some other native syntax
>> for metafunctions.
>
> And I don't understand why people expect the standard to emerge
> perfectly formed from some magic source of an ideal language.
> If you think there should be something else then get involved and
propose it.
I can understand your viewpoint, but even if I wasn't involved in IT at
the time, and certainly not at that level, I can still say that it
always seemed rather obvious to me that the "metafunction concept" of
Boost.MPL is a workaround because of missing native language features
(using template, class, typedef).
so I was surprised that it was introduced into the standard when there
was a chance to natively support metafunctions.
that isn't saying that anyone did a bad job when introducing type
traits, and I'm sorry if it was perceived that way.