template <class OuterA1, class OuterA2, class... InnerAllocs>
bool operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b) noexcept;
Returns: If sizeof...(InnerAllocs) is zero,
a.outer_allocator() == b.outer_allocator()
otherwise
a.outer_allocator() == b.outer_allocator() && a.inner_allocator() == b.inner_allocator()
template <class OuterA1, class OuterA2, class... InnerAllocs>
bool operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b) noexcept;