TLA  Line data    Source code

       1                 : // Copyright (c) 2016-2022 Thomas Fussell
       2                 : // Copyright (c) 2024-2025 xlnt-community
       3                 : //
       4                 : // Permission is hereby granted, free of charge, to any person obtaining a copy
       5                 : // of this software and associated documentation files (the "Software"), to deal
       6                 : // in the Software without restriction, including without limitation the rights
       7                 : // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
       8                 : // copies of the Software, and to permit persons to whom the Software is
       9                 : // furnished to do so, subject to the following conditions:
      10                 : //
      11                 : // The above copyright notice and this permission notice shall be included in
      12                 : // all copies or substantial portions of the Software.
      13                 : //
      14                 : // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      15                 : // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      16                 : // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      17                 : // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      18                 : // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      19                 : // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      20                 : // THE SOFTWARE
      21                 : //
      22                 : // @license: http://www.opensource.org/licenses/mit-license.php
      23                 : // @author: see AUTHORS file
      24                 : 
      25                 : #pragma once
      26                 : 
      27                 : #include <functional> // for std::hash
      28                 : 
      29                 : namespace xlnt {
      30                 : 
      31                 : /// <summary>
      32                 : /// Allows a scoped enum (aka "enum class") to be used as a key
      33                 : /// in a std::unordered_map.
      34                 : /// </summary>
      35                 : template <typename Enum>
      36                 : struct scoped_enum_hash
      37                 : {
      38                 :     /// <summary>
      39                 :     /// Cast the enumeration e to a std::size_t and hash that value using std::hash.
      40                 :     /// </summary>
      41 CBC         331 :     std::size_t operator()(Enum e) const
      42                 :     {
      43                 :         static std::hash<std::size_t> hasher;
      44             331 :         return hasher(static_cast<std::size_t>(e));
      45                 :     }
      46                 : };
      47                 : 
      48                 : } // namespace xlnt