ceph/src/boost/libs/spirit/include/boost/spirit/home/qi/numeric/numeric_utils.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 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_NUMERIC_UTILS_APRIL_17_2006_0830AM)
   9 #define BOOST_SPIRIT_NUMERIC_UTILS_APRIL_17_2006_0830AM
  10
  11 #if defined(_MSC_VER)
  12 #pragma once
  13 #endif
  14
  15 #include <boost/spirit/home/support/assert_msg.hpp>
  16 #include <boost/spirit/home/qi/detail/assign_to.hpp>
  17 #include <boost/spirit/home/qi/numeric/detail/numeric_utils.hpp>
  18 #include <boost/assert.hpp>
  19 #include <boost/mpl/assert.hpp>
  20
  21 namespace boost { namespace spirit { namespace qi
  22 {
  23     ///////////////////////////////////////////////////////////////////////////
  24     //  Extract the prefix sign (- or +), return true if a '-' was found
  25     ///////////////////////////////////////////////////////////////////////////
  26     template <typename Iterator>
  27     inline bool
  28     extract_sign(Iterator& first, Iterator const& last)
  29     {
  30         (void)last;                  // silence unused warnings
  31         BOOST_ASSERT(first != last); // precondition
  32
  33         // Extract the sign
  34         bool neg = *first == '-';
  35         if (neg || (*first == '+'))
  36         {
  37             ++first;
  38             return neg;
  39         }
  40         return false;
  41     }
  42
  43     ///////////////////////////////////////////////////////////////////////////
  44     // Low level unsigned integer parser
  45     ///////////////////////////////////////////////////////////////////////////
  46     template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits
  47       , bool Accumulate = false, bool IgnoreOverflowDigits = false>
  48     struct extract_uint
  49     {
  50         // check template parameter 'Radix' for validity
  51         BOOST_SPIRIT_ASSERT_MSG(
  52             Radix >= 2 && Radix <= 36,
  53             not_supported_radix, ());
  54
  55         template <typename Iterator>
  56         inline static bool call(Iterator& first, Iterator const& last, T& attr_)
  57         {
  58             if (first == last)
  59                 return false;
  60
  61             typedef detail::extract_int<
  62                 T
  63               , Radix
  64               , MinDigits
  65               , MaxDigits
  66               , detail::positive_accumulator<Radix>
  67               , Accumulate
  68               , IgnoreOverflowDigits>
  69             extract_type;
  70
  71             Iterator save = first;
  72             if (!extract_type::parse(first, last,
  73                 detail::cast_unsigned<T>::call(attr_)))
  74             {
  75                 first = save;
  76                 return false;
  77             }
  78             return true;
  79         }
  80
  81         template <typename Iterator, typename Attribute>
  82         inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_)
  83         {
  84             // this case is called when Attribute is not T
  85             T attr_local;
  86             if (call(first, last, attr_local))
  87             {
  88                 traits::assign_to(attr_local, attr_);
  89                 return true;
  90             }
  91             return false;
  92         }
  93     };
  94
  95     ///////////////////////////////////////////////////////////////////////////
  96     // Low level signed integer parser
  97     ///////////////////////////////////////////////////////////////////////////
  98     template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits>
  99     struct extract_int
 100     {
 101         // check template parameter 'Radix' for validity
 102         BOOST_SPIRIT_ASSERT_MSG(
 103             Radix == 2 || Radix == 8 || Radix == 10 || Radix == 16,
 104             not_supported_radix, ());
 105
 106         template <typename Iterator>
 107         inline static bool call(Iterator& first, Iterator const& last, T& attr_)
 108         {
 109             if (first == last)
 110                 return false;
 111
 112             typedef detail::extract_int<
 113                 T, Radix, MinDigits, MaxDigits>
 114             extract_pos_type;
 115
 116             typedef detail::extract_int<
 117                 T, Radix, MinDigits, MaxDigits, detail::negative_accumulator<Radix> >
 118             extract_neg_type;
 119
 120             Iterator save = first;
 121             bool hit = extract_sign(first, last);
 122             if (hit)
 123                 hit = extract_neg_type::parse(first, last, attr_);
 124             else
 125                 hit = extract_pos_type::parse(first, last, attr_);
 126
 127             if (!hit)
 128             {
 129                 first = save;
 130                 return false;
 131             }
 132             return true;
 133         }
 134
 135         template <typename Iterator, typename Attribute>
 136         inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_)
 137         {
 138             // this case is called when Attribute is not T
 139             T attr_local;
 140             if (call(first, last, attr_local))
 141             {
 142                 traits::assign_to(attr_local, attr_);
 143                 return true;
 144             }
 145             return false;
 146         }
 147     };
 148 }}}
 149
 150 #endif