If the standard library checks the index in std::vector::operator[]
(_GLIBCXX_ASSERTIONS, libc++ hardening modes), ByteVector::operator[]
and List::operator[] now check the index against their own size and
abort if it is out of range, as std::vector does.
The std::vector check alone is not enough: a ByteVector created by
mid() shares the buffer of the original byte vector, so an index past
the end of the smaller vector still passes it. List::operator[] walks
a std::list, which these checks do not cover.
Builds without these macros are unchanged; a GCC Release build of
libtag produces identical code. The Ubuntu CI job now builds with
-D_GLIBCXX_ASSERTIONS so that the tests run with the checks enabled.
Nathan ChandrasekarandGitHub
50ca520b27