ceph/src/Beast/include/beast/core/detail/ci_char_traits.hpp

   1 //
   2 // Copyright (c) 2013-2017 Vinnie Falco (vinnie dot falco at gmail dot 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
   8 #ifndef BEAST_DETAIL_CI_CHAR_TRAITS_HPP
   9 #define BEAST_DETAIL_CI_CHAR_TRAITS_HPP
  10
  11 #include <boost/range/algorithm/equal.hpp>
  12 #include <boost/utility/string_ref.hpp>
  13
  14 namespace beast {
  15 namespace detail {
  16
  17 inline
  18 char
  19 tolower(signed char c)
  20 {
  21     static unsigned char constexpr tab[256] = {
  22           0,   1,   2,   3,    4,   5,   6,   7,    8,   9,  10,  11,   12,  13,  14,  15,
  23          16,  17,  18,  19,   20,  21,  22,  23,   24,  25,  26,  27,   28,  29,  30,  31,
  24          32,  33,  34,  35,   36,  37,  38,  39,   40,  41,  42,  43,   44,  45,  46,  47,
  25          48,  49,  50,  51,   52,  53,  54,  55,   56,  57,  58,  59,   60,  61,  62,  63,
  26          64,  97,  98,  99,  100, 101, 102, 103,  104, 105, 106, 107,  108, 109, 110, 111,
  27         112, 113, 114, 115,  116, 117, 118, 119,  120, 121, 122,  91,   92,  93,  94,  95,
  28          96,  97,  98,  99,  100, 101, 102, 103,  104, 105, 106, 107,  108, 109, 110, 111,
  29         112, 113, 114, 115,  116, 117, 118, 119,  120, 121, 122, 123,  124, 125, 126, 127,
  30         128, 129, 130, 131,  132, 133, 134, 135,  136, 137, 138, 139,  140, 141, 142, 143,
  31         144, 145, 146, 147,  148, 149, 150, 151,  152, 153, 154, 155,  156, 157, 158, 159,
  32         160, 161, 162, 163,  164, 165, 166, 167,  168, 169, 170, 171,  172, 173, 174, 175,
  33         176, 177, 178, 179,  180, 181, 182, 183,  184, 185, 186, 187,  188, 189, 190, 191,
  34         192, 193, 194, 195,  196, 197, 198, 199,  200, 201, 202, 203,  204, 205, 206, 207,
  35         208, 209, 210, 211,  212, 213, 214, 215,  216, 217, 218, 219,  220, 221, 222, 223,
  36         224, 225, 226, 227,  228, 229, 230, 231,  232, 233, 234, 235,  236, 237, 238, 239,
  37         240, 241, 242, 243,  244, 245, 246, 247,  248, 249, 250, 251,  252, 253, 254, 255
  38     };
  39     return static_cast<char>(
  40         tab[static_cast<unsigned char>(c)]);
  41 }
  42
  43 template<std::size_t N>
  44 inline
  45 boost::string_ref
  46 string_helper(const char (&s)[N])
  47 {
  48     return boost::string_ref{s, N-1};
  49 }
  50
  51 template<class T>
  52 inline
  53 T const&
  54 string_helper(T const& t)
  55 {
  56     return t;
  57 }
  58
  59 // Case-insensitive less
  60 struct ci_less
  61 {
  62     static bool const is_transparent = true;
  63
  64     template<class S1, class S2>
  65     bool
  66     operator()(S1 const& lhs, S2 const& rhs) const noexcept
  67     {
  68         using std::begin;
  69         using std::end;
  70         auto const s1 = string_helper(lhs);
  71         auto const s2 = string_helper(rhs);
  72         return std::lexicographical_compare(
  73             begin(s1), end(s1), begin(s2), end(s2),
  74             [](char lhs, char rhs)
  75             {
  76                 return tolower(lhs) < tolower(rhs);
  77             }
  78         );
  79     }
  80 };
  81
  82 // Case-insensitive equal
  83 struct ci_equal_pred
  84 {
  85     bool
  86     operator()(char c1, char c2) const noexcept
  87     {
  88         return tolower(c1) == tolower(c2);
  89     }
  90 };
  91
  92 // Case-insensitive equal
  93 template<class S1, class S2>
  94 bool
  95 ci_equal(S1 const& lhs, S2 const& rhs)
  96 {
  97     return boost::range::equal(
  98         string_helper(lhs), string_helper(rhs),
  99             ci_equal_pred{});
 100 }
 101
 102 } // detail
 103 } // beast
 104
 105 #endif