template<class Allocator2> friend bool operator==(const basic_stacktrace& x, const basic_stacktrace<Allocator2>& y) noexcept;

Returns: equal(x.begin(), x.end(), y.begin(), y.end()).

template<class Allocator2> friend strong_ordering operator<=>(const basic_stacktrace& x, const basic_stacktrace<Allocator2>& y) noexcept;

Returns: x.size() <=> y.size() if x.size() != y.size(); lexicographical_compare_three_way(x.begin(), x.end(), y.begin(), y.end()) otherwise.