Replace BOOST_SYSTEM_NO_DEPRECATED with BOOST_SYSTEM_ENABLE_DEPRECATED

[pdimov]

No description provided.

[pdimov]

Beman, can you please take a look at this and decide whether we want it in 1.66, as there are just a few days left.

[Beman]

On Sun, Oct 22, 2017 at 2:05 PM, Peter Dimov ***@***.***> wrote: Beman, can you please take a look at this and decide whether we want it in 1.66, as there are just a few days left.

I've been thinking about it on and off all day. Not because there is anything wrong with your P/R; go ahead and apply it. But for the longer term, C++ software developers need better tools for dealing with library changes over time. We need to be able to tell at compile time if a translation unit does certain things and have the compile time ability to issue warnings if the translation unit does something like calls deprecated functions. More about this as soon as the committee's premeeting mailing ships in a few days.

…

--Beman

[pdimov]

OK, let's see how it goes.

[pdimov]

As a next step, I think that we need to consider routing boost::error_code and friends to std::error_code et al, if the compiler supports the latter. This can also potentially break code, of course. But "use std::error_code if it exists, otherwise boost::error_code" is something many libraries already do, and due to error_code being an interface type, this creates incompatibilities between libraries that choose one over the other.

[ned14]

The patchset looked good.

I agree with the idea that error_code, error_category etc become mapped to the std editions when on C++ 11 or better. It allows all the header only libraries currently incorrectly using header only Boost.System to become correct if compiled on C++ 11 or better.

One might consider announcing in the release notes that the next Boost will be the last to use the local implementation in C++ 11 or better.

Also, one might consider also rerouting boost::current_exception() to std::current_exception(). The latter is surely always going to be equal or better to the Boost implementation.

[pdimov]

This last suggestion would be better placed in https://github.com/boostorg/exception. It didn't have issues enabled, but it does now. :-)