https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114147
--- Comment #2 from __vic <victor.dyachenko at protonmail dot com> ---
Shouldn't this be added?
template<typename _Alloc,
_ExplicitDefaultCtor<is_object<_Alloc>::value, _T1, _T2> = true>
explicit
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a)
: _Inherited(__tag, __a) { }
