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.venv/Lib/site-packages/pyarrow/include/arrow/util/hash_util.h

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+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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
+
+namespace arrow {
+namespace internal {
+
+// ----------------------------------------------------------------------
+// BEGIN Hash utilities from Boost
+
+namespace detail {
+
+#if defined(_MSC_VER)
+#define ARROW_HASH_ROTL32(x, r) _rotl(x, r)
+#else
+#define ARROW_HASH_ROTL32(x, r) (x << r) | (x >> (32 - r))
+#endif
+
+template <typename SizeT>
+inline void hash_combine_impl(SizeT& seed, SizeT value) {
+  seed ^= value + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+}
+
+inline void hash_combine_impl(uint32_t& h1, uint32_t k1) {
+  const uint32_t c1 = 0xcc9e2d51;
+  const uint32_t c2 = 0x1b873593;
+
+  k1 *= c1;
+  k1 = ARROW_HASH_ROTL32(k1, 15);
+  k1 *= c2;
+
+  h1 ^= k1;
+  h1 = ARROW_HASH_ROTL32(h1, 13);
+  h1 = h1 * 5 + 0xe6546b64;
+}
+
+#undef ARROW_HASH_ROTL32
+
+}  // namespace detail
+
+template <class T>
+inline void hash_combine(std::size_t& seed, T const& v) {
+  std::hash<T> hasher;
+  return ::arrow::internal::detail::hash_combine_impl(seed, hasher(v));
+}
+
+// END Hash utilities from Boost
+// ----------------------------------------------------------------------
+
+}  // namespace internal
+}  // namespace arrow