ceph/src/boost/boost/json/detail/hash_combine.hpp

   1 //
   2 // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com)
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // Official repository: https://github.com/boostorg/json
   8 //
   9
  10 #ifndef BOOST_JSON_DETAIL_HASH_COMBINE_HPP
  11 #define BOOST_JSON_DETAIL_HASH_COMBINE_HPP
  12
  13 BOOST_JSON_NS_BEGIN
  14 namespace detail {
  15
  16 inline
  17 std::size_t
  18 hash_combine(
  19     std::size_t seed,
  20     std::size_t h) noexcept
  21 {
  22   seed ^= h + 0x9e3779b9 + (seed << 6U) + (seed >> 2U);
  23   return seed;
  24 }
  25
  26 inline
  27 std::size_t
  28 hash_combine_commutative(
  29     std::size_t lhs,
  30     std::size_t rhs) noexcept
  31 {
  32   return  lhs ^ rhs;
  33 }
  34
  35 } // detail
  36 BOOST_JSON_NS_END
  37
  38 #endif