ceph/src/boost/boost/beast/core/detail/static_string.hpp

   1 //
   2 // Copyright (c) 2016-2019 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 // Official repository: https://github.com/boostorg/beast
   8 //
   9
  10 #ifndef BOOST_BEAST_DETAIL_STATIC_STRING_HPP
  11 #define BOOST_BEAST_DETAIL_STATIC_STRING_HPP
  12
  13 #include <boost/beast/core/string.hpp>
  14 #include <boost/assert.hpp>
  15 #include <iterator>
  16 #include <type_traits>
  17
  18 namespace boost {
  19 namespace beast {
  20 namespace detail {
  21
  22 // Because k-ballo said so
  23 template<class T>
  24 using is_input_iterator =
  25     std::integral_constant<bool,
  26         ! std::is_integral<T>::value>;
  27
  28 template<class CharT, class Traits>
  29 int
  30 lexicographical_compare(
  31     CharT const* s1, std::size_t n1,
  32     CharT const* s2, std::size_t n2)
  33 {
  34     if(n1 < n2)
  35         return Traits::compare(
  36             s1, s2, n1) <= 0 ? -1 : 1;
  37     if(n1 > n2)
  38         return Traits::compare(
  39             s1, s2, n2) >= 0 ? 1 : -1;
  40     return Traits::compare(s1, s2, n1);
  41 }
  42
  43 template<class CharT, class Traits>
  44 int
  45 lexicographical_compare(
  46     basic_string_view<CharT, Traits> s1,
  47     CharT const* s2, std::size_t n2)
  48 {
  49     return detail::lexicographical_compare<
  50         CharT, Traits>(s1.data(), s1.size(), s2, n2);
  51 }
  52
  53 template<class CharT, class Traits>
  54 int
  55 lexicographical_compare(
  56     basic_string_view<CharT, Traits> s1,
  57     basic_string_view<CharT, Traits> s2)
  58 {
  59     return detail::lexicographical_compare<CharT, Traits>(
  60         s1.data(), s1.size(), s2.data(), s2.size());
  61 }
  62
  63 // Maximum number of characters in the decimal
  64 // representation of a binary number. This includes
  65 // the potential minus sign.
  66 //
  67 inline
  68 std::size_t constexpr
  69 max_digits(std::size_t bytes)
  70 {
  71     return static_cast<std::size_t>(
  72         bytes * 2.41) + 1 + 1;
  73 }
  74
  75 template<class CharT, class Integer, class Traits>
  76 CharT*
  77 raw_to_string(
  78     CharT* buf, Integer x, std::true_type)
  79 {
  80     if(x == 0)
  81     {
  82         Traits::assign(*--buf, '0');
  83         return buf;
  84     }
  85     if(x < 0)
  86     {
  87         x = -x;
  88         for(;x > 0; x /= 10)
  89             Traits::assign(*--buf ,
  90                 "0123456789"[x % 10]);
  91         Traits::assign(*--buf, '-');
  92         return buf;
  93     }
  94     for(;x > 0; x /= 10)
  95         Traits::assign(*--buf ,
  96             "0123456789"[x % 10]);
  97     return buf;
  98 }
  99
 100 template<class CharT, class Integer, class Traits>
 101 CharT*
 102 raw_to_string(
 103     CharT* buf, Integer x, std::false_type)
 104 {
 105     if(x == 0)
 106     {
 107         *--buf = '0';
 108         return buf;
 109     }
 110     for(;x > 0; x /= 10)
 111         Traits::assign(*--buf ,
 112             "0123456789"[x % 10]);
 113     return buf;
 114 }
 115
 116 template<
 117     class CharT,
 118     class Integer,
 119     class Traits = std::char_traits<CharT>>
 120 CharT*
 121 raw_to_string(CharT* last, std::size_t size, Integer i)
 122 {
 123     boost::ignore_unused(size);
 124     BOOST_ASSERT(size >= max_digits(sizeof(Integer)));
 125     return raw_to_string<CharT, Integer, Traits>(
 126         last, i, std::is_signed<Integer>{});
 127 }
 128
 129 } // detail
 130 } // beast
 131 } // boost
 132
 133 #endif