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Diffstat (limited to 'boost/spirit/home/x3/support/numeric_utils/extract_int.hpp')
-rw-r--r-- | boost/spirit/home/x3/support/numeric_utils/extract_int.hpp | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/boost/spirit/home/x3/support/numeric_utils/extract_int.hpp b/boost/spirit/home/x3/support/numeric_utils/extract_int.hpp new file mode 100644 index 0000000000..aa80cdd6ea --- /dev/null +++ b/boost/spirit/home/x3/support/numeric_utils/extract_int.hpp @@ -0,0 +1,147 @@ +/*============================================================================= + Copyright (c) 2001-2014 Joel de Guzman + Copyright (c) 2011 Jan Frederick Eick + + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +==============================================================================*/ +#if !defined(BOOST_SPIRIT_X3_EXTRACT_INT_APRIL_17_2006_0830AM) +#define BOOST_SPIRIT_X3_EXTRACT_INT_APRIL_17_2006_0830AM + +#if defined(_MSC_VER) +#pragma once +#endif + +#include <boost/spirit/home/x3/support/traits/move_to.hpp> +#include <boost/spirit/home/x3/support/numeric_utils/detail/extract_int.hpp> +#include <boost/assert.hpp> + +namespace boost { namespace spirit { namespace x3 +{ + /////////////////////////////////////////////////////////////////////////// + // Extract the prefix sign (- or +), return true if a '-' was found + /////////////////////////////////////////////////////////////////////////// + template <typename Iterator> + inline bool + extract_sign(Iterator& first, Iterator const& last) + { + (void)last; // silence unused warnings + BOOST_ASSERT(first != last); // precondition + + // Extract the sign + bool neg = *first == '-'; + if (neg || (*first == '+')) + { + ++first; + return neg; + } + return false; + } + + /////////////////////////////////////////////////////////////////////////// + // Low level unsigned integer parser + /////////////////////////////////////////////////////////////////////////// + template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits + , bool Accumulate = false> + struct extract_uint + { + // check template parameter 'Radix' for validity + static_assert( + (Radix >= 2 && Radix <= 36), + "Error Unsupported Radix"); + + template <typename Iterator> + inline static bool call(Iterator& first, Iterator const& last, T& attr) + { + if (first == last) + return false; + + typedef detail::extract_int< + T + , Radix + , MinDigits + , MaxDigits + , detail::positive_accumulator<Radix> + , Accumulate> + extract_type; + + Iterator save = first; + if (!extract_type::parse(first, last, + detail::cast_unsigned<T>::call(attr))) + { + first = save; + return false; + } + return true; + } + + template <typename Iterator, typename Attribute> + inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_) + { + // this case is called when Attribute is not T + T attr; + if (call(first, last, attr)) + { + traits::move_to(attr, attr_); + return true; + } + return false; + } + }; + + /////////////////////////////////////////////////////////////////////////// + // Low level signed integer parser + /////////////////////////////////////////////////////////////////////////// + template <typename T, unsigned Radix, unsigned MinDigits, int MaxDigits> + struct extract_int + { + // check template parameter 'Radix' for validity + static_assert( + (Radix == 2 || Radix == 8 || Radix == 10 || Radix == 16), + "Error Unsupported Radix"); + + template <typename Iterator> + inline static bool call(Iterator& first, Iterator const& last, T& attr) + { + if (first == last) + return false; + + typedef detail::extract_int< + T, Radix, MinDigits, MaxDigits> + extract_pos_type; + + typedef detail::extract_int< + T, Radix, MinDigits, MaxDigits, detail::negative_accumulator<Radix> > + extract_neg_type; + + Iterator save = first; + bool hit = extract_sign(first, last); + if (hit) + hit = extract_neg_type::parse(first, last, attr); + else + hit = extract_pos_type::parse(first, last, attr); + + if (!hit) + { + first = save; + return false; + } + return true; + } + + template <typename Iterator, typename Attribute> + inline static bool call(Iterator& first, Iterator const& last, Attribute& attr_) + { + // this case is called when Attribute is not T + T attr; + if (call(first, last, attr)) + { + traits::move_to(attr, attr_); + return true; + } + return false; + } + }; +}}} + +#endif |