avoid thrust copy

src/utilities/include/par.h

@@ -174,9 +174,30 @@ STL_DYNAMIC_BACKEND_VOID(uninitialized_fill)
 STL_DYNAMIC_BACKEND_VOID(uninitialized_copy)
 STL_DYNAMIC_BACKEND_VOID(stable_sort)
 STL_DYNAMIC_BACKEND_VOID(fill)
-STL_DYNAMIC_BACKEND_VOID(copy)
 STL_DYNAMIC_BACKEND_VOID(inclusive_scan)
-STL_DYNAMIC_BACKEND_VOID(copy_n)
+
+// there are some issues with thrust copy
+template <typename InputIterator, typename OutputIterator>
+OutputIterator copy(ExecutionPolicy policy, InputIterator first,
+                    InputIterator last, OutputIterator result) {
+#if MANIFOLD_PAR == 'T' && \
+    (TBB_INTERFACE_VERSION >= 10000 && __has_include(<pstl/glue_execution_defs.h>))
+  if (policy == ExecutionPolicy::Par)
+    return std::copy(std::execution::par_unseq, first, last, result);
+#endif
+  return std::copy(first, last, result);
+}
+
+template <typename InputIterator, typename OutputIterator>
+OutputIterator copy_n(ExecutionPolicy policy, InputIterator first, size_t n,
+                      OutputIterator result) {
+#if MANIFOLD_PAR == 'T' && \
+    (TBB_INTERFACE_VERSION >= 10000 && __has_include(<pstl/glue_execution_defs.h>))
+  if (policy == ExecutionPolicy::Par)
+    return std::copy_n(std::execution::par_unseq, first, n, result);
+#endif
+  return std::copy_n(first, n, result);
+}
 
 // void implies that the user have to specify the return type in the template
 // argument, as we are unable to deduce it