use cuda::std::span instead of std::span in nvexec bulk test

Author: ericniebler

test/nvexec/bulk.cpp

@@ -4,7 +4,7 @@
 #include "nvexec/stream_context.cuh"
 #include "common.cuh"
 
-#include <span>
+#include <cuda/std/span>
 
 namespace ex = stdexec;
 
@@ -170,10 +170,12 @@ namespace {
     cudaMallocManaged(&inout, nelems * sizeof(double));
 
     auto task =
-      stdexec::transfer_just(ctx.get_scheduler(), std::span<double>{inout, nelems})
-      | stdexec::bulk(nelems, [](std::size_t i, std::span<double> out) { out[i] = i; })
-      | stdexec::let_value([](std::span<double> out) { return stdexec::just(out); })
-      | stdexec::bulk(nelems, [](std::size_t i, std::span<double> out) { out[i] = 2.0 * out[i]; });
+      stdexec::transfer_just(ctx.get_scheduler(), cuda::std::span<double>{inout, nelems})
+      | stdexec::bulk(nelems, [](std::size_t i, cuda::std::span<double> out) { out[i] = i; })
+      | stdexec::let_value([](cuda::std::span<double> out) { return stdexec::just(out); })
+      | stdexec::bulk(nelems, [](std::size_t i, cuda::std::span<double> out) {
+          out[i] = 2.0 * out[i];
+        });
 
     stdexec::sync_wait(std::move(task)).value();