[boost] Strange libstdc++ versions in travis-ci testers

Subject: [boost] Strange libstdc++ versions in travis-ci testers
From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2018-06-28 19:14:18

Hi Everyone,
Maybe someone could help me understand the configuration on the travis-ci
testers. Whenever I push a new commit I get a number of failures from
travis-ci about missing std::is_trivially_default_constructible from the
standard library; like here:
https://travis-ci.org/boostorg/optional/builds/397519342?utm_source=email&utm_medium=notification

Some tests with Boost.Predef indicate that they are clang compiler 3.X, and
clang 5 with libstdc++ of strange version nubers: macro BOOST_LIB_STD_GNU
gives values 450400026 and 460700026, which would correspond to releases
2015-04-26 and 2016-07-26, but when I look at the release notes for GCC
there are no releases mentioned of these dates:
https://gcc.gnu.org/news.html

Maybe someone knows what versions of libstdc++  these are? Or maybe I am
missing something obvious?

Regards,
&rzej;