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diff --git a/extern/draco/draco/src/draco/core/hash_utils.h b/extern/draco/draco/src/draco/core/hash_utils.h
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+++ b/extern/draco/draco/src/draco/core/hash_utils.h
@@ -0,0 +1,64 @@
+// Copyright 2016 The Draco Authors.
+//
+// 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.
+//
+#ifndef DRACO_CORE_HASH_UTILS_H_
+#define DRACO_CORE_HASH_UTILS_H_
+
+#include <stdint.h>
+
+#include <cstddef>
+#include <functional>
+
+namespace draco {
+
+template <typename T1, typename T2>
+size_t HashCombine(T1 a, T2 b) {
+  const size_t hash1 = std::hash<T1>()(a);
+  const size_t hash2 = std::hash<T2>()(b);
+  return (hash1 << 2) ^ (hash2 << 1);
+}
+
+template <typename T>
+size_t HashCombine(T a, size_t hash) {
+  const size_t hasha = std::hash<T>()(a);
+  return (hash) ^ (hasha + 239);
+}
+
+inline uint64_t HashCombine(uint64_t a, uint64_t b) {
+  return (a + 1013) ^ (b + 107) << 1;
+}
+
+// Will never return 1 or 0.
+uint64_t FingerprintString(const char *s, size_t len);
+
+// Hash for std::array.
+template <typename T>
+struct HashArray {
+  size_t operator()(const T &a) const {
+    size_t hash = 79;  // Magic number.
+    for (unsigned int i = 0; i < std::tuple_size<T>::value; ++i) {
+      hash = HashCombine(hash, ValueHash(a[i]));
+    }
+    return hash;
+  }
+
+  template <typename V>
+  size_t ValueHash(const V &val) const {
+    return std::hash<V>()(val);
+  }
+};
+
+}  // namespace draco
+
+#endif  // DRACO_CORE_HASH_UTILS_H_