Re: nullptr vs 0

From: Christian Mazakas (christian.mazakas_at_[hidden])
Date: 2022-05-23 15:33:22

> The use of NULL as a null pointer is perfectly valid, in the sense of
both
> formal C++ compliance and code readability.

In spirit, I wholeheartedly agree with this.

Unfortunately, this issue seems to come from a perfect storm of elements.
We've
had to solve something like this for Unordered as well.

https://github.com/boostorg/unordered/issues/39

It seems to be users including Boost as a non-system header and also using
`-Wzero-as-null-pointer-constant` with clang. We don't control how users
ultimately choose to add Boost to their projects and it should be a goal to
remove any warnings we generate in their builds, within reason.

In this case, using a simple macro `BOOST_NULLPTR` is easy and
straight-forward
for both maintainers and potential contributors.
- Christian