C++17 cleanup: traits replace ::value with _v (#10319)

- replace `std::is_*<T>::value` with `std::is_*_v<T>`

Please suggest any other C++17 tech debts.

Authors:
  - Karthikeyan (https://github.com/karthikeyann)

Approvers:
  - Conor Hoekstra (https://github.com/codereport)
  - Christopher Harris (https://github.com/cwharris)

URL: #10319

cpp/benchmarks/common/generate_input.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -69,15 +69,14 @@ distribution_id default_distribution_id()
   return distribution_id::GEOMETRIC;
 }
 
-template <typename T,
-          std::enable_if_t<!std::is_unsigned<T>::value && cudf::is_numeric<T>()>* = nullptr>
+template <typename T, std::enable_if_t<!std::is_unsigned_v<T> && cudf::is_numeric<T>()>* = nullptr>
 distribution_id default_distribution_id()
 {
   return distribution_id::NORMAL;
 }
 
 template <typename T,
-          std::enable_if_t<!std::is_same_v<T, bool> && std::is_unsigned<T>::value &&
+          std::enable_if_t<!std::is_same_v<T, bool> && std::is_unsigned_v<T> &&
                            cudf::is_numeric<T>()>* = nullptr>
 distribution_id default_distribution_id()
 {
@@ -226,7 +225,7 @@ class data_profile {
  public:
   template <
     typename T,
-    typename std::enable_if_t<!std::is_same_v<T, bool> && std::is_integral<T>::value, T>* = nullptr>
+    typename std::enable_if_t<!std::is_same_v<T, bool> && std::is_integral_v<T>, T>* = nullptr>
   distribution_params<T> get_distribution_params() const
   {
     auto it = int_params.find(cudf::type_to_id<T>());
@@ -239,7 +238,7 @@ class data_profile {
     }
   }
 
-  template <typename T, typename std::enable_if_t<std::is_floating_point<T>::value, T>* = nullptr>
+  template <typename T, typename std::enable_if_t<std::is_floating_point_v<T>, T>* = nullptr>
   distribution_params<T> get_distribution_params() const
   {
     auto it = float_params.find(cudf::type_to_id<T>());
@@ -307,7 +306,7 @@ class data_profile {
   // discrete distributions (integers, strings, lists). Otherwise the call with have no effect.
   template <typename T,
             typename Type_enum,
-            typename std::enable_if_t<std::is_integral<T>::value, T>* = nullptr>
+            typename std::enable_if_t<std::is_integral_v<T>, T>* = nullptr>
   void set_distribution_params(Type_enum type_or_group,
                                distribution_id dist,
                                T lower_bound,
@@ -331,7 +330,7 @@ class data_profile {
   // have continuous distributions (floating point types). Otherwise the call with have no effect.
   template <typename T,
             typename Type_enum,
-            typename std::enable_if_t<std::is_floating_point<T>::value, T>* = nullptr>
+            typename std::enable_if_t<std::is_floating_point_v<T>, T>* = nullptr>
   void set_distribution_params(Type_enum type_or_group,
                                distribution_id dist,
                                T lower_bound,

cpp/benchmarks/common/random_distribution_factory.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,7 +24,7 @@
 /**
  * @brief Generates a normal(binomial) distribution between zero and upper_bound.
  */
-template <typename T, typename std::enable_if_t<std::is_integral<T>::value, T>* = nullptr>
+template <typename T, typename std::enable_if_t<std::is_integral_v<T>, T>* = nullptr>
 auto make_normal_dist(T upper_bound)
 {
   using uT = typename std::make_unsigned<T>::type;
@@ -42,7 +42,7 @@ auto make_normal_dist(T upper_bound)
   return std::normal_distribution<T>(mean, stddev);
 }
 
-template <typename T, typename std::enable_if_t<std::is_integral<T>::value, T>* = nullptr>
+template <typename T, typename std::enable_if_t<std::is_integral_v<T>, T>* = nullptr>
 auto make_uniform_dist(T range_start, T range_end)
 {
   return std::uniform_int_distribution<T>(range_start, range_end);
@@ -62,7 +62,7 @@ double geometric_dist_p(T range_size)
   return p ? p : std::numeric_limits<double>::epsilon();
 }
 
-template <typename T, typename std::enable_if_t<std::is_integral<T>::value, T>* = nullptr>
+template <typename T, typename std::enable_if_t<std::is_integral_v<T>, T>* = nullptr>
 auto make_geometric_dist(T range_start, T range_end)
 {
   using uT = typename std::make_unsigned<T>::type;
@@ -82,7 +82,7 @@ auto make_geometric_dist(T range_start, T range_end)
 template <typename T>
 using distribution_fn = std::function<T(std::mt19937&)>;
 
-template <typename T, typename std::enable_if_t<std::is_integral<T>::value, T>* = nullptr>
+template <typename T, typename std::enable_if_t<std::is_integral_v<T>, T>* = nullptr>
 distribution_fn<T> make_distribution(distribution_id did, T lower_bound, T upper_bound)
 {
   switch (did) {

cpp/benchmarks/type_dispatcher/type_dispatcher.cu

@@ -42,7 +42,7 @@ struct Functor {
 };
 
 template <class Float, FunctorType ft>
-struct Functor<Float, ft, typename std::enable_if_t<std::is_floating_point<Float>::value>> {
+struct Functor<Float, ft, typename std::enable_if_t<std::is_floating_point_v<Float>>> {
   static __device__ Float f(Float x)
   {
     if (ft == BANDWIDTH_BOUND) {

cpp/include/cudf/ast/detail/operators.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,10 +35,10 @@ namespace detail {
 
 // Traits for valid operator / type combinations
 template <typename Op, typename LHS, typename RHS>
-constexpr bool is_valid_binary_op = cuda::std::is_invocable<Op, LHS, RHS>::value;
+constexpr bool is_valid_binary_op = cuda::std::is_invocable_v<Op, LHS, RHS>;
 
 template <typename Op, typename T>
-constexpr bool is_valid_unary_op = cuda::std::is_invocable<Op, T>::value;
+constexpr bool is_valid_unary_op = cuda::std::is_invocable_v<Op, T>;
 
 /**
  * @brief Operator dispatcher
@@ -301,8 +301,8 @@ struct operator_functor<ast_operator::MOD, false> {
 
   template <typename LHS,
             typename RHS,
-            typename CommonType                                    = std::common_type_t<LHS, RHS>,
-            std::enable_if_t<std::is_integral<CommonType>::value>* = nullptr>
+            typename CommonType                               = std::common_type_t<LHS, RHS>,
+            std::enable_if_t<std::is_integral_v<CommonType>>* = nullptr>
   __device__ inline auto operator()(LHS lhs, RHS rhs)
     -> decltype(static_cast<CommonType>(lhs) % static_cast<CommonType>(rhs))
   {
@@ -336,8 +336,8 @@ struct operator_functor<ast_operator::PYMOD, false> {
 
   template <typename LHS,
             typename RHS,
-            typename CommonType                                    = std::common_type_t<LHS, RHS>,
-            std::enable_if_t<std::is_integral<CommonType>::value>* = nullptr>
+            typename CommonType                               = std::common_type_t<LHS, RHS>,
+            std::enable_if_t<std::is_integral_v<CommonType>>* = nullptr>
   __device__ inline auto operator()(LHS lhs, RHS rhs)
     -> decltype(((static_cast<CommonType>(lhs) % static_cast<CommonType>(rhs)) +
                  static_cast<CommonType>(rhs)) %
@@ -542,7 +542,7 @@ template <>
 struct operator_functor<ast_operator::SIN, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::sin(input))
   {
     return std::sin(input);
@@ -553,7 +553,7 @@ template <>
 struct operator_functor<ast_operator::COS, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::cos(input))
   {
     return std::cos(input);
@@ -564,7 +564,7 @@ template <>
 struct operator_functor<ast_operator::TAN, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::tan(input))
   {
     return std::tan(input);
@@ -575,7 +575,7 @@ template <>
 struct operator_functor<ast_operator::ARCSIN, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::asin(input))
   {
     return std::asin(input);
@@ -586,7 +586,7 @@ template <>
 struct operator_functor<ast_operator::ARCCOS, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::acos(input))
   {
     return std::acos(input);
@@ -597,7 +597,7 @@ template <>
 struct operator_functor<ast_operator::ARCTAN, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::atan(input))
   {
     return std::atan(input);
@@ -608,7 +608,7 @@ template <>
 struct operator_functor<ast_operator::SINH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::sinh(input))
   {
     return std::sinh(input);
@@ -619,7 +619,7 @@ template <>
 struct operator_functor<ast_operator::COSH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::cosh(input))
   {
     return std::cosh(input);
@@ -630,7 +630,7 @@ template <>
 struct operator_functor<ast_operator::TANH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::tanh(input))
   {
     return std::tanh(input);
@@ -641,7 +641,7 @@ template <>
 struct operator_functor<ast_operator::ARCSINH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::asinh(input))
   {
     return std::asinh(input);
@@ -652,7 +652,7 @@ template <>
 struct operator_functor<ast_operator::ARCCOSH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::acosh(input))
   {
     return std::acosh(input);
@@ -663,7 +663,7 @@ template <>
 struct operator_functor<ast_operator::ARCTANH, false> {
   static constexpr auto arity{1};
 
-  template <typename InputT, std::enable_if_t<std::is_floating_point<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_floating_point_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::atanh(input))
   {
     return std::atanh(input);
@@ -741,13 +741,13 @@ struct operator_functor<ast_operator::ABS, false> {
   static constexpr auto arity{1};
 
   // Only accept signed or unsigned types (both require is_arithmetic<T> to be true)
-  template <typename InputT, std::enable_if_t<std::is_signed<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_signed_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(std::abs(input))
   {
     return std::abs(input);
   }
 
-  template <typename InputT, std::enable_if_t<std::is_unsigned<InputT>::value>* = nullptr>
+  template <typename InputT, std::enable_if_t<std::is_unsigned_v<InputT>>* = nullptr>
   __device__ inline auto operator()(InputT input) -> decltype(input)
   {
     return input;

cpp/include/cudf/column/column_device_view.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2021, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -380,16 +380,15 @@ class alignas(16) column_device_view : public detail::column_device_view_base {
    */
   struct index_element_fn {
     template <typename IndexType,
-              CUDF_ENABLE_IF(is_index_type<IndexType>() and std::is_unsigned<IndexType>::value)>
+              CUDF_ENABLE_IF(is_index_type<IndexType>() and std::is_unsigned_v<IndexType>)>
     __device__ size_type operator()(column_device_view const& indices, size_type index)
     {
       return static_cast<size_type>(indices.element<IndexType>(index));
     }
 
     template <typename IndexType,
               typename... Args,
-              CUDF_ENABLE_IF(not(is_index_type<IndexType>() and
-                                 std::is_unsigned<IndexType>::value))>
+              CUDF_ENABLE_IF(not(is_index_type<IndexType>() and std::is_unsigned_v<IndexType>))>
     __device__ size_type operator()(Args&&... args)
     {
       cudf_assert(false and "dictionary indices must be an unsigned integral type");

cpp/include/cudf/detail/aggregation/aggregation.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2021, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -108,7 +108,7 @@ using corresponding_operator_t = typename corresponding_operator<k>::type;
 template <aggregation::Kind k>
 constexpr bool has_corresponding_operator()
 {
-  return !std::is_same<typename corresponding_operator<k>::type, void>::value;
+  return !std::is_same_v<typename corresponding_operator<k>::type, void>;
 }
 
 template <typename Source,
@@ -602,16 +602,15 @@ struct identity_initializer {
   }
 
   template <typename T, aggregation::Kind k>
-  std::enable_if_t<not std::is_same<corresponding_operator_t<k>, void>::value, T>
+  std::enable_if_t<not std::is_same_v<corresponding_operator_t<k>, void>, T>
   identity_from_operator()
   {
     using DeviceType = device_storage_type_t<T>;
     return corresponding_operator_t<k>::template identity<DeviceType>();
   }
 
   template <typename T, aggregation::Kind k>
-  std::enable_if_t<std::is_same<corresponding_operator_t<k>, void>::value, T>
-  identity_from_operator()
+  std::enable_if_t<std::is_same_v<corresponding_operator_t<k>, void>, T> identity_from_operator()
   {
     CUDF_FAIL("Unable to get identity/sentinel from device operator");
   }

cpp/include/cudf/detail/aggregation/aggregation.hpp

@@ -1158,10 +1158,9 @@ constexpr bool is_sum_product_agg(aggregation::Kind k)
 
 // Summing/Multiplying integers of any type, always use int64_t accumulator
 template <typename Source, aggregation::Kind k>
-struct target_type_impl<
-  Source,
-  k,
-  std::enable_if_t<std::is_integral<Source>::value && is_sum_product_agg(k)>> {
+struct target_type_impl<Source,
+                        k,
+                        std::enable_if_t<std::is_integral_v<Source> && is_sum_product_agg(k)>> {
   using type = int64_t;
 };
 
@@ -1179,7 +1178,7 @@ template <typename Source, aggregation::Kind k>
 struct target_type_impl<
   Source,
   k,
-  std::enable_if_t<std::is_floating_point<Source>::value && is_sum_product_agg(k)>> {
+  std::enable_if_t<std::is_floating_point_v<Source> && is_sum_product_agg(k)>> {
   using type = Source;
 };
 
@@ -1539,7 +1538,7 @@ data_type target_type(data_type source_type, aggregation::Kind k);
 template <typename Source, aggregation::Kind k>
 constexpr inline bool is_valid_aggregation()
 {
-  return (not std::is_void<target_type_t<Source, k>>::value);
+  return (not std::is_void_v<target_type_t<Source, k>>);
 }
 
 /**