Date: Mon, 10 Sep 2018 12:27:01 +0200 From: Jan Beich <jbeich@FreeBSD.org> To: Alexey Dokuchaev <danfe@FreeBSD.org> Cc: svn-ports-head@freebsd.org, svn-ports-all@freebsd.org, ports-committers@freebsd.org Subject: Re: svn commit: r479222 - in head/devel: boost-all boost-libs boost-python-libs Message-ID: <musp-zlze-wny@FreeBSD.org> In-Reply-To: <20180910044521.GA90644@FreeBSD.org> (Alexey Dokuchaev's message of "Mon, 10 Sep 2018 04:45:21 %2B0000") References: <201809080053.w880rArT081869@repo.freebsd.org> <20180910044521.GA90644@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Alexey Dokuchaev <danfe@FreeBSD.org> writes: > On Sat, Sep 08, 2018 at 12:53:10AM +0000, Jan Beich wrote: > >> New Revision: 479222 >> URL: https://svnweb.freebsd.org/changeset/ports/479222 >> >> Log: >> devel/boost-all: switch to C++17 on FreeBSD >= 11.2 > > Why? In order to keep system Boost usable for most consumers and avoid missing on new features on future upgrades. C++17 usage in ports is growing. If something starts to depend on C++17-only feature in Boost it'd require using non-default flavor but without variable dependencies depending on default and non-default conflicting flavor is impossible. > >> +# XXX Drop conditional after 10.4 EOL as both libstdc++ 7 and libc++ 6 >> +# have near complete C++17 support. >> +.if exists(/usr/lib/libstdc++.so) || exists(/usr/include/c++/v1/__undef_macros) >> +USES+= compiler:c++17-lang >> +USE_CXXSTD= gnu++17 >> +.else >> USES+= compiler:c++14-lang >> USE_CXXSTD= gnu++14 >> +.endif > > Shouldn't things like Boost use the least supported version by default? The opposite. Boost built against older C++ standards may be unusable in ports that use it with later standards. Bumping to C++17 is simply a continuation of C++03 -> C++11 -> C++14 change. https://github.com/DragonFlyBSD/DeltaPorts/pull/690 # C++11 https://github.com/boostorg/system/issues/24 # C++14 https://lists.boost.org/Archives/boost/2018/08/242885.php # bikeshed https://lists.boost.org/Archives/boost/2018/08/242770.php # ABI discussion https://stackoverflow.com/questions/46746878/is-it-safe-to-link-c17-c14-and-c11-objects # libstdc++ ABI
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?musp-zlze-wny>