get.hpp 1.7 KB

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  1. /// \file
  2. // Range v3 library
  3. //
  4. // Copyright Eric Niebler 2013-present
  5. //
  6. // Use, modification and distribution is subject to the
  7. // Boost Software License, Version 1.0. (See accompanying
  8. // file LICENSE_1_0.txt or copy at
  9. // http://www.boost.org/LICENSE_1_0.txt)
  10. //
  11. // Project home: https://github.com/ericniebler/range-v3
  12. //
  13. #ifndef RANGES_V3_UTILITY_GET_HPP
  14. #define RANGES_V3_UTILITY_GET_HPP
  15. #include <meta/meta.hpp>
  16. #include <concepts/concepts.hpp>
  17. #include <range/v3/detail/adl_get.hpp>
  18. #include <range/v3/detail/prologue.hpp>
  19. namespace ranges
  20. {
  21. /// \addtogroup group-utility Utility
  22. /// @{
  23. ///
  24. /// \cond
  25. namespace _get_
  26. {
  27. /// \endcond
  28. // clang-format off
  29. template<std::size_t I, typename TupleLike>
  30. constexpr auto CPP_auto_fun(get)(TupleLike &&t)
  31. (
  32. return detail::adl_get<I>(static_cast<TupleLike &&>(t))
  33. )
  34. template<typename T, typename TupleLike>
  35. constexpr auto CPP_auto_fun(get)(TupleLike &&t)
  36. (
  37. return detail::adl_get<T>(static_cast<TupleLike &&>(t))
  38. )
  39. // clang-format on
  40. template<typename T>
  41. T & get(meta::id_t<T> & value) noexcept
  42. {
  43. return value;
  44. }
  45. template<typename T>
  46. T const & get(meta::id_t<T> const & value) noexcept
  47. {
  48. return value;
  49. }
  50. template<typename T>
  51. T && get(meta::id_t<T> && value) noexcept
  52. {
  53. return static_cast<T &&>(value);
  54. }
  55. /// \cond
  56. } // namespace _get_
  57. using namespace _get_;
  58. /// \endcond
  59. /// @}
  60. } // namespace ranges
  61. #include <range/v3/detail/epilogue.hpp>
  62. #endif