digit_table.hpp 2.1 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162
  1. // Copyright 2018 Ulf Adams
  2. //
  3. // The contents of this file may be used under the terms of the Apache License,
  4. // Version 2.0.
  5. //
  6. // (See accompanying file LICENSE-Apache or copy at
  7. // http://www.apache.org/licenses/LICENSE-2.0)
  8. //
  9. // Alternatively, the contents of this file may be used under the terms of
  10. // the Boost Software License, Version 1.0.
  11. // (See accompanying file LICENSE-Boost or copy at
  12. // https://www.boost.org/LICENSE_1_0.txt)
  13. //
  14. // Unless required by applicable law or agreed to in writing, this software
  15. // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  16. // KIND, either express or implied.
  17. /*
  18. This is a derivative work
  19. */
  20. #ifndef BOOST_JSON_DETAIL_RYU_DETAIL_DIGIT_TABLE_HPP
  21. #define BOOST_JSON_DETAIL_RYU_DETAIL_DIGIT_TABLE_HPP
  22. #include <boost/json/detail/config.hpp>
  23. namespace boost {
  24. namespace json {
  25. namespace detail {
  26. namespace ryu {
  27. namespace detail {
  28. // A table of all two-digit numbers. This is used to speed up decimal digit
  29. // generation by copying pairs of digits into the final output.
  30. inline
  31. char const
  32. (&DIGIT_TABLE() noexcept)[200]
  33. {
  34. static constexpr char arr[200] = {
  35. '0','0','0','1','0','2','0','3','0','4','0','5','0','6','0','7','0','8','0','9',
  36. '1','0','1','1','1','2','1','3','1','4','1','5','1','6','1','7','1','8','1','9',
  37. '2','0','2','1','2','2','2','3','2','4','2','5','2','6','2','7','2','8','2','9',
  38. '3','0','3','1','3','2','3','3','3','4','3','5','3','6','3','7','3','8','3','9',
  39. '4','0','4','1','4','2','4','3','4','4','4','5','4','6','4','7','4','8','4','9',
  40. '5','0','5','1','5','2','5','3','5','4','5','5','5','6','5','7','5','8','5','9',
  41. '6','0','6','1','6','2','6','3','6','4','6','5','6','6','6','7','6','8','6','9',
  42. '7','0','7','1','7','2','7','3','7','4','7','5','7','6','7','7','7','8','7','9',
  43. '8','0','8','1','8','2','8','3','8','4','8','5','8','6','8','7','8','8','8','9',
  44. '9','0','9','1','9','2','9','3','9','4','9','5','9','6','9','7','9','8','9','9' };
  45. return arr;
  46. }
  47. } // detail
  48. } // ryu
  49. } // detail
  50. } // namespace json
  51. } // namespace boost
  52. #endif