Re: [boost] C++03 / C++11 compatibility question for compiled libraries

Subject: Re: [boost] C++03 / C++11 compatibility question for compiled libraries
From: degski (degski_at_[hidden])
Date: 2018-02-09 16:59:05

On 9 February 2018 at 10:15, Paul A. Bristow via Boost <
boost_at_[hidden]> wrote:

> Historically Boost has always taken the line that *each library* is
> allowed to set its minimum compiler/standard level.
>

This is a slightly dis-ingenious statement, I think. Boost's first release
dates from 1999, so after publication of C++98. C++03 was an bug fix
release. Which means that, in case we are talking about going towards
C++11, we can see that since its' inception boost has not encountered any
(significant) new standard(s). So far, support for C++11 has not been
ubiquitous, so historically it makes sense not to push for moving to C++11.
In the meanwhile, the landscape looks different.

> More complicated is if an existing library wants to up its requirements.
> Sometimes this can be achieved using macro tests - and Boost is massively
> complicated by doing this already.
>

And with new standards rolling in every three years, and (future) removal
of deprecated features and more frequent fixes, this is only gonna get
worse, i.e. Peter D. proposal to move to positive macros.

> Many libraries author who want to make a big step like moving to
> C++11(++)  may find it easier to have a separate new version 2 (3...) as
> this allows them to take full advantage of new features to do things better
> (and cut the crap).

Moving to using a C++11 compliant compiler is not a big step IMO, you don't
need to use any C++11 feature iff you don't want to.

>   This clearly suits those that don't want to update compilers.
>

That is just mad cow disease !

> Authors wanting to make a breaking change like requiring C++11(++) can
> also take the line that those who won't update Boost can only continue
> using C++03 by freezing at an old Boost version.
>

Exactly, if you don't want to upgrade compiler, it's better to use the old
libs, they we're at the time well tested with the compilers of the day.

degski