Clarify CUDA C++ version restrictions

diff --git a/cmake/configure/configure_1_cuda.cmake b/cmake/configure/configure_1_cuda.cmake
index c82b96b08f19652bc94f32f37c847000074a787c..f4813f83dd870d020e1e33977f2f744bc1be85d0 100644 (file)
--- a/cmake/configure/configure_1_cuda.cmake
+++ b/cmake/configure/configure_1_cuda.cmake
@@ -57,7 +57,8 @@ MACRO(FEATURE_CUDA_FIND_EXTERNAL var)
     ENDIF()
 
     #
-    # CUDA 8.0 requires C++11 support, CUDA 9.0 requires C++14 support.
+    # CUDA Toolkit 8 is incompatible with C++14,
+    # CUDA Toolkit 9 and CUDA Toolkit 10 are incompatible with C++17.
     # Make sure that deal.II is configured appropriately
     #
     MACRO(_cuda_ensure_feature_off _version _feature)