From ec5baea36da04c592b94f9dff8e2589bfaf97ebd Mon Sep 17 00:00:00 2001
From: Rong Ou <rong.ou@gmail.com>
Date: Tue, 25 Aug 2020 16:09:10 -0700
Subject: [PATCH] review feedback

---
 thrust/system/cuda/detail/transform_scan.h      | 5 +++++
 thrust/system/detail/generic/transform_scan.inl | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/thrust/system/cuda/detail/transform_scan.h b/thrust/system/cuda/detail/transform_scan.h
index aad83c843..fbf70b0a7 100644
--- a/thrust/system/cuda/detail/transform_scan.h
+++ b/thrust/system/cuda/detail/transform_scan.h
@@ -50,8 +50,13 @@ transform_inclusive_scan(execution_policy<Derived> &policy,
                          TransformOp                transform_op,
                          ScanOp                     scan_op)
 {
+  // Use the input iterator's value type per https://wg21.link/P0571
   using input_type = typename thrust::iterator_value<InputIt>::type;
+#if THRUST_CPP_DIALECT < 2017
   using result_type = typename std::result_of<TransformOp(input_type)>::type;
+#else
+  using result_type = std::invoke_result_t<TransformOp, input_type>;
+#endif
 
   typedef typename iterator_traits<InputIt>::difference_type size_type;
   size_type num_items = static_cast<size_type>(thrust::distance(first, last));
diff --git a/thrust/system/detail/generic/transform_scan.inl b/thrust/system/detail/generic/transform_scan.inl
index 567bf92da..31053cd10 100644
--- a/thrust/system/detail/generic/transform_scan.inl
+++ b/thrust/system/detail/generic/transform_scan.inl
@@ -48,8 +48,13 @@ __host__ __device__
                                           UnaryFunction unary_op,
                                           BinaryFunction binary_op)
 {
+  // Use the input iterator's value type per https://wg21.link/P0571
   using InputType = typename thrust::iterator_value<InputIterator>::type;
+#if THRUST_CPP_DIALECT < 2017
   using ValueType = typename std::result_of<UnaryFunction(InputType)>::type;
+#else
+  using ValueType = std::invoke_result_t<UnaryFunction, InputType>;
+#endif
 
   thrust::transform_iterator<UnaryFunction, InputIterator, ValueType> _first(first, unary_op);
   thrust::transform_iterator<UnaryFunction, InputIterator, ValueType> _last(last, unary_op);