Re: The new Boost 17.0.0

From: Hans Dembinski (hans.dembinski_at_[hidden])
Date: 2020-11-27 09:46:40

> On 27. Nov 2020, at 09:58, Antony Polukhin via Boost <boost_at_[hidden]> wrote:
> 
> == The Solution
> TL;DR: we need a C++17 fork of Boost with close to 0 dependencies
> between libraries and namespace versioning.

I am personally fine with a C++17 fork, but that means dropping Boost Serialization among other things, right?

Boost Histogram has level 2 dependencies without Boost Serialization, which is opt-in. With Boost Serialization is has level 18, because Boost Serialization depends on the world. AFAIK rewriting Boost Serialization to drop Boost MPL would be a major effort.

Besides that, demanding 0 dependencies has serious drawbacks. Boost Histogram uses Boost functionality where there is no equivalent in the stdlib, not even in C++17 (Boost config, Boost throw_exception, Boost mp11, Boost core). I already reimplemented functionality in Boost Histogram that was originally found in other Boost libs to reduce coupling, like Boost Iterator and Boost Multiprecision. Boost Beast does this, too, it has its own variant type and more.

A non-fundamental library like Histogram or Beast has the choice to either suffer a significant loss of functionality or use its own private implementation of Boost functionality to give the appearance of low dependencies. This inflates the private code of these libraries and maintaining private (duplicated) implementations is frankly crazy. We bundle Boost to make use of **synergies** between the libs. I should not use my private (potentially buggy) implementation of Boost iterator, I should use the official maintained (and hopefully less buggy) one.

Best regards,
Hans