Test Thrust iterator system propagation (#5875)

Author: bernhardmgruber

thrust/testing/catch2_test_iterator_traits.cu

@@ -0,0 +1,45 @@
+#include <thrust/device_vector.h>
+#include <thrust/iterator/counting_iterator.h>
+#include <thrust/iterator/iterator_traits.h>
+#include <thrust/iterator/transform_iterator.h>
+#include <thrust/iterator/zip_iterator.h>
+
+#include "catch2_test_helper.h"
+
+TEST_CASE("iterator system propagation - any system", "[iterators]")
+{
+  [[maybe_unused]] auto counting_it = thrust::make_counting_iterator(0);
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(counting_it)>, thrust::any_system_tag>);
+
+  [[maybe_unused]] auto transform_it = thrust::make_transform_iterator(counting_it, thrust::square<>{});
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(transform_it)>, thrust::any_system_tag>);
+
+  [[maybe_unused]] auto zip_it = thrust::make_zip_iterator(counting_it, transform_it);
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(zip_it)>, thrust::any_system_tag>);
+}
+
+TEST_CASE("iterator system propagation - device system", "[iterators]")
+{
+  [[maybe_unused]] auto d_vec    = thrust::device_vector<int>{};
+  [[maybe_unused]] auto d_vec_it = d_vec.begin();
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(d_vec_it)>, thrust::device_system_tag>);
+
+  [[maybe_unused]] auto transform_it = thrust::make_transform_iterator(d_vec_it, thrust::square<>{});
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(transform_it)>, thrust::device_system_tag>);
+
+  [[maybe_unused]] auto zip_it = thrust::make_zip_iterator(d_vec_it, transform_it);
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(zip_it)>, thrust::device_system_tag>);
+}
+
+TEST_CASE("iterator system propagation - any and device system", "[iterators]")
+{
+  [[maybe_unused]] auto d_vec    = thrust::device_vector<int>{};
+  [[maybe_unused]] auto d_vec_it = d_vec.begin();
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(d_vec_it)>, thrust::device_system_tag>);
+
+  [[maybe_unused]] auto counting_it = thrust::make_counting_iterator(0);
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(counting_it)>, thrust::any_system_tag>);
+
+  [[maybe_unused]] auto zip_it = thrust::make_zip_iterator(d_vec_it, counting_it);
+  STATIC_REQUIRE(cuda::std::is_same_v<thrust::iterator_system_t<decltype(zip_it)>, thrust::device_system_tag>);
+}