[oneDPL][ranges][zip_view] + implementation fix for 'operator-' betwe…

…en zip_view::iterators

include/oneapi/dpl/pstl/zip_view_impl.h

@@ -189,13 +189,13 @@ class zip_view : public std::ranges::view_interface<zip_view<Views...>> {
         friend constexpr auto operator<=>(const iterator& x, const iterator& y)
             requires all_random_access<Const, Views...>
         {
-            return x.current_ == y.current_;
+            return x.current_ <=> y.current_;
         }
 
         friend constexpr auto operator-(const iterator& x, const iterator& y)
             requires all_random_access<Const, Views...>
         {
-            return std::get<0>(x.current_) - std::get<0>(y.current_);
+            return x.distance_to_it(y.current_, std::make_index_sequence<sizeof...(Views)>());
         }
 
         friend constexpr iterator operator+(iterator it, difference_type n)
@@ -233,6 +233,15 @@ class zip_view : public std::ranges::view_interface<zip_view<Views...>> {
             ( (min = std::min(min, (std::get<In>(current_) - std::get<In>(sentinels)))) , ... );
             return min;
         }
+        template <std::size_t... In>
+        constexpr std::common_type_t<std::conditional_t<!Const, std::ranges::range_difference_t<Views>,
+                                                                std::ranges::range_difference_t<const Views>>...>
+        distance_to_it(const iterator it, std::index_sequence<0, In...>) const {
+            auto min = std::get<0>(it.current_) - std::get<0>(current_);
+
+            ( (min = std::min(min, (std::get<In>(it.current_) - std::get<In>(current_)))) , ... );
+            return min;
+        }
 
         friend class zip_view;