add --with-system-boost configure option for using system-wide boost headers

[real-dam]

This is the last one of the "use system $lib" series.

[asfernandes]

This is public header file. So I think name must be better FB_USE_SYSTEM_BOOST.

[aafemt]

Taking into account that C++11 features are fully available, do we still need boost?

[real-dam]

Taking into account that C++11 features are fully available, do we still need boost?

I like the idea of replacing an external dependency with a compiler feature. Hopefully someone more fluent in C++ than me would try it.

[asfernandes]

Taking into account that C++11 features are fully available, do we still need boost?

We didn't discussed C++11 in public headers yet. I support it.

[asfernandes]

This is misspelled (bools).

[asfernandes]

How that will work for public headers?

Will you put a dependency for boost in firebird-client-dev (or the name you use) package?

Will you deploy fb-boost headers in that package?

Will the user also need to use the define?

[real-dam]

How that will work for public headers?

Will you put a dependency for boost in firebird-client-dev (or the name you use) package?

Will you deploy fb-boost headers in that package?

Will the user also need to use the define?

Good question. Requiring that all consumers of firebird/Message.h define USE_SYSTEM_BOOST would be bad.

Perhaps I should reverse the define and rename it to USE_FB_BOOST? This way consumers using the Debian package would only need to have boost around, maybe pulled by a dependency.

That dependency, while technically needed, is not present in firebird3.0 packages which have a similar patch (crudely using system boost and replacing FB_BOOST_xxx with BOOST_xxx in Message.h) and nobody complained for the last 5+ years. I guess some softer form of dependency would be enough.

Will update the PR with USE_FB_BOOST and reverse meaning.

[aafemt]

nobody complained for the last 5+ years.

It just means that nobody uses Messages.h.

[real-dam]

Will update the PR with USE_FB_BOOST and reverse meaning.
Oh, but that would mean that any Message.h consumers that have it from non-packaged Firebird would need the define. Not good either.

I think the approach used in fb3 Debian packages is the least evil.

The cleanest way from consumer side would be to have Messages.h with either include <...boost...> (plus a dependency) or include "...boost...", both hard-coded and not controlled by a define.

fb3 debs took one approach at this, patching the installed files.

An approach that controls the output via --with-system-boost would require similar sort of patching, for example via sed. Shouldn't be a problem since this affects only posix builds. Will be kind of ugly, but should work.

[real-dam]

This became as good as patching during package build with the added benefit that including it upstream will make the functionality available for other downstream distributions.