chore: import upstream snapshot with attribution

test/cpp/phi/core/random.h

@@ -0,0 +1,47 @@
+/* Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License. */
+
+#pragma once
+
+#include <random>
+#include <type_traits>
+
+namespace phi {
+namespace tests {
+
+template <typename T,
+          typename =
+              typename std::enable_if<std::is_arithmetic<T>::value>::type>
+class RandomGenerator {
+  using distribution_type =
+      typename std::conditional<std::is_integral<T>::value,
+                                std::uniform_int_distribution<T>,
+                                std::uniform_real_distribution<T>>::type;
+
+  std::default_random_engine engine;
+  distribution_type distribution;
+
+ public:
+  auto operator()() -> decltype(distribution(engine)) {
+    return distribution(engine);
+  }
+};
+
+template <typename Container, typename T = typename Container::value_type>
+auto make_generator(Container const&) -> decltype(RandomGenerator<T>()) {
+  return RandomGenerator<T>();
+}
+
+}  // namespace tests
+}  // namespace phi