fix win

include/boost/histogram/storage_adaptor.hpp

@@ -83,6 +83,8 @@ struct element_adaptor_generic {
 template <typename T>
 using element_adaptor =
     mp11::mp_if<is_accumulator_set<T>, element_adaptor_accumulator_set,
+                // is_incrementable is used instead of std::is_arithmetic, which also
+                // works with wrapped integers like copyable_atomic<int>
                 mp11::mp_if<detail::is_incrementable<T>, element_adaptor_incrementable,
                             element_adaptor_generic>>;