https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100475
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:fe993b469c528230d9a01e1ae2208610f960dd9f commit r12-856-gfe993b469c528230d9a01e1ae2208610f960dd9f Author: Patrick Palka <ppa...@redhat.com> Date: Tue May 18 00:28:44 2021 -0400 libstdc++: Fix up semiregular-box partial specialization [PR100475] This makes the in-place constructor of our partial specialization of __box for already-semiregular types perform direct-non-list-initialization (in accordance with the specification of the primary template), and additionally makes the member function data() use std::__addressof. libstdc++-v3/ChangeLog: PR libstdc++/100475 * include/std/ranges (__box::__box): Use non-list-initialization in member initializer list of in-place constructor of the partial specialization for semiregular types. (__box::operator->): Use std::__addressof. * testsuite/std/ranges/adaptors/detail/semiregular_box.cc (test02): New test. * testsuite/std/ranges/single_view.cc (test04): New test.