diff --git a/include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h b/include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h
index 29277b8d7db..a609867dee8 100644
--- a/include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h
+++ b/include/oneapi/dpl/pstl/hetero/algorithm_impl_hetero.h
@@ -901,6 +901,7 @@ __pattern_copy_if(__hetero_tag<_BackendTag>, _ExecutionPolicy&& __exec, _Iterato
     if (__first == __last)
         return __result_first;
 
+    auto __n = __last - __first;
     auto __keep1 = oneapi::dpl::__ranges::__get_sycl_range<__par_backend_hetero::access_mode::read, _Iterator1>();
     auto __buf1 = __keep1(__first, __last);
     auto __keep2 = oneapi::dpl::__ranges::__get_sycl_range<__par_backend_hetero::access_mode::write, _Iterator2>();
diff --git a/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h b/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h
index 93ee410c36a..b03b73c78e7 100644
--- a/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h
+++ b/include/oneapi/dpl/pstl/hetero/algorithm_ranges_impl_hetero.h
@@ -540,18 +540,18 @@ std::pair<oneapi::dpl::__internal::__difference_t<_Range1>, oneapi::dpl::__inter
 __pattern_copy_if(__hetero_tag<_BackendTag> __tag, _ExecutionPolicy&& __exec, _Range1&& __rng1, _Range2&& __rng2,
                   _Predicate __pred, _Assign __assign)
 {
-    using _Index = oneapi::dpl::__internal::__difference_t<_Range2>;
+    using _Index = std::size_t; //TODO
     _Index __n = __rng1.size();
     if (__n == 0 || __rng2.empty())
         return {0, 0};
 
     auto __res = oneapi::dpl::__par_backend_hetero::__parallel_copy_if_out_lim(
         _BackendTag{}, std::forward<_ExecutionPolicy>(__exec), std::forward<_Range1>(__rng1),
-        std::forward<_Range2>(__rng2), __pred, __assign).get();
+        std::forward<_Range2>(__rng2), __pred, __assign);
 
-    std::array<_Index, _2> __idx;
+    std::array<_Index, 2> __idx;
     __res.get_values(__idx); //a blocking call
-    return {__idx[0], __idx[1];
+    return {__idx[1], __idx[0]}; //__parallel_copy_if_out_lim returns {last index in output, last index in input}
 }
 
 #if _ONEDPL_CPP20_RANGES_PRESENT
diff --git a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl.h b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl.h
index 995b74bfd78..6f72994eca1 100644
--- a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl.h
+++ b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl.h
@@ -316,7 +316,7 @@ struct __parallel_scan_submitter<_CustomName, __internal::__optional_kernel_name
         // Storage for the results of scan for each workgroup
 
         using __result_and_scratch_storage_t = __result_and_scratch_storage<_ExecutionPolicy, _Type>;
-        __result_and_scratch_storage_t __result_and_scratch{__exec, 1, __n_groups + 1};
+        __result_and_scratch_storage_t __result_and_scratch{__exec, 2, __n_groups + 1};
 
         _PRINT_INFO_IN_DEBUG_MODE(__exec, __wgroup_size, __max_cu);
 
@@ -1235,6 +1235,7 @@ __parallel_scan_copy(oneapi::dpl::__internal::__device_backend_tag __backend_tag
                      _InRng&& __in_rng, _OutRng&& __out_rng, _CreateMaskOp __create_mask_op,
                      _CopyByMaskOp __copy_by_mask_op)
 {
+    using  _Size = decltype(__out_rng.size());
     using _ReduceOp = std::plus<_Size>;
     using _Assigner = unseq_backend::__scan_assigner;
     using _NoAssign = unseq_backend::__scan_no_assign;
@@ -1370,6 +1371,7 @@ auto
 __parallel_copy_if_out_lim(oneapi::dpl::__internal::__device_backend_tag __backend_tag, _ExecutionPolicy&& __exec,
                    _InRng&& __in_rng, _OutRng&& __out_rng, _Pred __pred, _Assign __assign = _Assign{})
 {
+    using _Size = decltype(__out_rng.size());
     using _ReduceOp = std::plus<_Size>;
     using _CreateOp = unseq_backend::__create_mask<_Pred, _Size>;
     using _CopyOp = unseq_backend::__copy_by_mask<_ReduceOp, _Assign,
diff --git a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_utils.h b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_utils.h
index 1b487cf90c6..c36032617fe 100644
--- a/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_utils.h
+++ b/include/oneapi/dpl/pstl/hetero/dpcpp/parallel_backend_sycl_utils.h
@@ -22,7 +22,7 @@
 #include <tuple>
 #include <algorithm>
 
-#include "../../iterator_impl.h"
+#include "../../iterator_impl.h" 
 
 #include "sycl_defs.h"
 #include "execution_sycl_defs.h"
@@ -683,8 +683,8 @@ struct __result_and_scratch_storage : __result_and_scratch_storage_base
         }
     }
 
-    template <typename _T, std::size_t _N>
-    void get_values(std::array<_T, _N>& __arr)
+    template <std::size_t _N>
+    void get_values(std::array<_T, _N>& __arr) const
     {
         assert(__result_n > 0);
         assert(_N == __result_n);
@@ -713,14 +713,14 @@ struct __result_and_scratch_storage : __result_and_scratch_storage_base
         return __get_value(idx);
     }
 
-    template <typename _Event, typename _T, std::size_t _N>
+    template <typename _Event, std::size_t _N>
     void
     __wait_and_get_value(_Event&& __event, std::array<_T, _N>& __arr) const
     {
         if (is_USM())
             __event.wait_and_throw();
 
-        return get_values(__arr);
+        get_values(__arr);
     }
 };
 
@@ -745,7 +745,7 @@ struct __wait_and_get_value
     constexpr void
     operator()(auto&& __event, const __result_and_scratch_storage<_ExecutionPolicy, _T>& __storage, std::array<_T, _N>& __arr)
     {
-        return __storage.__wait_and_get_value(__event, __arr);
+        __storage.__wait_and_get_value(__event, __arr);
     }
 
     template <typename _T>
@@ -812,9 +812,11 @@ class __future : private std::tuple<_Args...>
     }
 
     template <typename _T, std::size_t _N>
-    std::enable_if_t<sizeof...(_Args) > 0>
+    void
     get_values(std::array<_T, _N>& __arr)
     {
+        static_assert(sizeof...(_Args) > 0);
+        auto& __val = std::get<0>(*this);
         __wait_and_get_value{}(event(), __val, __arr);
     }
 
diff --git a/include/oneapi/dpl/pstl/hetero/dpcpp/unseq_backend_sycl.h b/include/oneapi/dpl/pstl/hetero/dpcpp/unseq_backend_sycl.h
index aabd0fcac27..9755c6affc7 100644
--- a/include/oneapi/dpl/pstl/hetero/dpcpp/unseq_backend_sycl.h
+++ b/include/oneapi/dpl/pstl/hetero/dpcpp/unseq_backend_sycl.h
@@ -625,12 +625,23 @@ struct __copy_by_mask
                 // ::std::tuple as operands, in all the other cases this is not necessary and no conversion
                 // is performed(i.e. __typle_type is the same type as its operand).
                 if(__out_idx < __out_acc.size())
+                {
                     __assigner(static_cast<__tuple_type>(get<0>(__in_acc[__item_idx])), __out_acc[__out_idx]);
+                    auto __last_out_idx = __wg_sums_ptr[(__n - 1) / __size_per_wg];
+                    if(__out_idx + 1 == __last_out_idx)
+                    {
+                        __ret_ptr[0] = __item_idx + 1, __ret_ptr[1] = __last_out_idx;
+                    }
+                }
+                else if(__out_idx == __out_acc.size())
+                {
+                    __ret_ptr[0] = __item_idx, __ret_ptr[1] = __out_idx;
+                }
         }
         if (__item_idx == 0)
         {
             //copy final result to output
-            *__ret_ptr = __wg_sums_ptr[(__n - 1) / __size_per_wg];
+            __ret_ptr[1] = __wg_sums_ptr[(__n - 1) / __size_per_wg];
         }
     }
 };