ceph/src/boost/boost/spirit/home/x3/support/numeric_utils/extract_int.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3     Copyright (c) 2011 Jan Frederick Eick
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8 #if !defined(BOOST_SPIRIT_X3_EXTRACT_INT_APRIL_17_2006_0830AM)
   9 #define BOOST_SPIRIT_X3_EXTRACT_INT_APRIL_17_2006_0830AM
  10
  11 #include <boost/spirit/home/x3/support/traits/move_to.hpp>
  12 #include <boost/spirit/home/x3/support/numeric_utils/detail/extract_int.hpp>
  13 #include <boost/assert.hpp>
  14
  15 namespace boost { namespace spirit { namespace x3
  16 {
  17     ///////////////////////////////////////////////////////////////////////////
  18     //  Extract the prefix sign (- or +), return true if a '-' was found
  19     ///////////////////////////////////////////////////////////////////////////
  20     template <typename Iterator>
  21     inline bool
  22     extract_sign(Iterator& first, Iterator const& last)
  23     {
  24         (void)last;                  // silence unused warnings
  25         BOOST_ASSERT(first != last); // precondition
  26
  27         // Extract the sign
  28         bool neg = *first == '-';
  29         if (neg || (*first == '+'))
  30         {
  31             ++first;
  32             return neg;
  33         }
  34         return false;
  35     }
  36
  37     ///////////////////////////////////////////////////////////////////////////
  38     // Low level unsigned integer parser
  39     ///////////////////////////////////////////////////////////////////////////
  40     template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits
  41       , bool Accumulate = false>
  42     struct extract_uint
  43     {
  44         // check template parameter 'Radix' for validity
  45         static_assert(
  46             (Radix >= 2 && Radix <= 36),
  47             "Error Unsupported Radix");
  48
  49         template <typename Iterator>
  50         inline static bool call(Iterator& first, Iterator const& last, T& attr)
  51         {
  52             if (first == last)
  53                 return false;
  54
  55             typedef detail::extract_int<
  56                 T
  57               , Radix
  58               , MinDigits
  59               , MaxDigits
  60               , detail::positive_accumulator<Radix>
  61               , Accumulate>
  62             extract_type;
  63
  64             Iterator save = first;
  65             if (!extract_type::parse(first, last,
  66                 detail::cast_unsigned<T>::call(attr)))
  67             {
  68                 first = save;
  69                 return false;
  70             }
  71             return true;
  72         }
  73
  74         template <typename Iterator, typename Attribute>
  75         inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_)
  76         {
  77             // this case is called when Attribute is not T
  78             T attr;
  79             if (call(first, last, attr))
  80             {
  81                 traits::move_to(attr, attr_);
  82                 return true;
  83             }
  84             return false;
  85         }
  86     };
  87
  88     ///////////////////////////////////////////////////////////////////////////
  89     // Low level signed integer parser
  90     ///////////////////////////////////////////////////////////////////////////
  91     template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits>
  92     struct extract_int
  93     {
  94         // check template parameter 'Radix' for validity
  95         static_assert(
  96             (Radix == 2 || Radix == 8 || Radix == 10 || Radix == 16),
  97             "Error Unsupported Radix");
  98
  99         template <typename Iterator>
 100         inline static bool call(Iterator& first, Iterator const& last, T& attr)
 101         {
 102             if (first == last)
 103                 return false;
 104
 105             typedef detail::extract_int<
 106                 T, Radix, MinDigits, MaxDigits>
 107             extract_pos_type;
 108
 109             typedef detail::extract_int<
 110                 T, Radix, MinDigits, MaxDigits, detail::negative_accumulator<Radix> >
 111             extract_neg_type;
 112
 113             Iterator save = first;
 114             bool hit = extract_sign(first, last);
 115             if (hit)
 116                 hit = extract_neg_type::parse(first, last, attr);
 117             else
 118                 hit = extract_pos_type::parse(first, last, attr);
 119
 120             if (!hit)
 121             {
 122                 first = save;
 123                 return false;
 124             }
 125             return true;
 126         }
 127
 128         template <typename Iterator, typename Attribute>
 129         inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_)
 130         {
 131             // this case is called when Attribute is not T
 132             T attr;
 133             if (call(first, last, attr))
 134             {
 135                 traits::move_to(attr, attr_);
 136                 return true;
 137             }
 138             return false;
 139         }
 140     };
 141 }}}
 142
 143 #endif