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

   1 //
   2 // Copyright (c) 2016-2017 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 // 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 inline
  45 int
  46 lexicographical_compare(
  47     basic_string_view<CharT, Traits> s1,
  48     CharT const* s2, std::size_t n2)
  49 {
  50     return lexicographical_compare<CharT, Traits>(
  51         s1.data(), s1.size(), s2, n2);
  52 }
  53
  54 template<class CharT, class Traits>
  55 inline
  56 int
  57 lexicographical_compare(
  58     basic_string_view<CharT, Traits> s1,
  59     basic_string_view<CharT, Traits> s2)
  60 {
  61     return lexicographical_compare<CharT, Traits>(
  62         s1.data(), s1.size(), s2.data(), s2.size());
  63 }
  64
  65 // Maximum number of characters in the decimal
  66 // representation of a binary number. This includes
  67 // the potential minus sign.
  68 //
  69 inline
  70 std::size_t constexpr
  71 max_digits(std::size_t bytes)
  72 {
  73     return static_cast<std::size_t>(
  74         bytes * 2.41) + 1 + 1;
  75 }
  76
  77 template<class CharT, class Integer, class Traits>
  78 CharT*
  79 raw_to_string(
  80     CharT* buf, Integer x, std::true_type)
  81 {
  82     if(x == 0)
  83     {
  84         Traits::assign(*--buf, '0');
  85         return buf;
  86     }
  87     if(x < 0)
  88     {
  89         x = -x;
  90         for(;x > 0; x /= 10)
  91             Traits::assign(*--buf ,
  92                 "0123456789"[x % 10]);
  93         Traits::assign(*--buf, '-');
  94         return buf;
  95     }
  96     for(;x > 0; x /= 10)
  97         Traits::assign(*--buf ,
  98             "0123456789"[x % 10]);
  99     return buf;
 100 }
 101
 102 template<class CharT, class Integer, class Traits>
 103 CharT*
 104 raw_to_string(
 105     CharT* buf, Integer x, std::false_type)
 106 {
 107     if(x == 0)
 108     {
 109         *--buf = '0';
 110         return buf;
 111     }
 112     for(;x > 0; x /= 10)
 113         Traits::assign(*--buf ,
 114             "0123456789"[x % 10]);
 115     return buf;
 116 }
 117
 118 template<
 119     class CharT,
 120     class Integer,
 121     class Traits = std::char_traits<CharT>>
 122 CharT*
 123 raw_to_string(CharT* last, std::size_t size, Integer i)
 124 {
 125     boost::ignore_unused(size);
 126     BOOST_ASSERT(size >= max_digits(sizeof(Integer)));
 127     return raw_to_string<CharT, Integer, Traits>(
 128         last, i, std::is_signed<Integer>{});
 129 }
 130
 131 } // detail
 132 } // beast
 133 } // boost
 134
 135 #endif