Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: /// \file null_regex_traits.hpp
Chris@16: /// Contains the definition of the null_regex_traits\<\> template, which is a
Chris@16: /// stub regex traits implementation that can be used by static and dynamic
Chris@16: /// regexes for searching non-character data.
Chris@16: //
Chris@16: //  Copyright 2008 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_XPRESSIVE_TRAITS_NULL_REGEX_TRAITS_HPP_EAN_10_04_2005
Chris@16: #define BOOST_XPRESSIVE_TRAITS_NULL_REGEX_TRAITS_HPP_EAN_10_04_2005
Chris@16: 
Chris@16: // MS compatible compilers support #pragma once
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <vector>
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/mpl/assert.hpp>
Chris@16: #include <boost/xpressive/detail/detail_fwd.hpp>
Chris@16: #include <boost/xpressive/detail/utility/never_true.hpp>
Chris@16: #include <boost/xpressive/detail/utility/ignore_unused.hpp>
Chris@16: 
Chris@16: namespace boost { namespace xpressive
Chris@16: {
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:     struct not_a_locale {};
Chris@16: }
Chris@16: 
Chris@16: struct regex_traits_version_1_tag;
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // null_regex_traits
Chris@16: //
Chris@16: /// \brief stub regex_traits for non-char data
Chris@16: ///
Chris@16: template<typename Elem>
Chris@16: struct null_regex_traits
Chris@16: {
Chris@16:     typedef Elem char_type;
Chris@16:     typedef std::vector<char_type> string_type;
Chris@16:     typedef detail::not_a_locale locale_type;
Chris@16:     typedef int char_class_type;
Chris@16:     typedef regex_traits_version_1_tag version_tag;
Chris@16: 
Chris@16:     /// Initialize a null_regex_traits object.
Chris@16:     ///
Chris@16:     null_regex_traits(locale_type = locale_type())
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /// Checks two null_regex_traits objects for equality
Chris@16:     ///
Chris@16:     /// \return true.
Chris@16:     bool operator ==(null_regex_traits<char_type> const &that) const
Chris@16:     {
Chris@16:         detail::ignore_unused(that);
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     /// Checks two null_regex_traits objects for inequality
Chris@16:     ///
Chris@16:     /// \return false.
Chris@16:     bool operator !=(null_regex_traits<char_type> const &that) const
Chris@16:     {
Chris@16:         detail::ignore_unused(that);
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     /// Convert a char to a Elem
Chris@16:     ///
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return Elem(ch).
Chris@16:     char_type widen(char ch) const
Chris@16:     {
Chris@16:         return char_type(ch);
Chris@16:     }
Chris@16: 
Chris@16:     /// Returns a hash value for a Elem in the range [0, UCHAR_MAX]
Chris@16:     ///
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return a value between 0 and UCHAR_MAX, inclusive.
Chris@16:     static unsigned char hash(char_type ch)
Chris@16:     {
Chris@16:         return static_cast<unsigned char>(ch);
Chris@16:     }
Chris@16: 
Chris@16:     /// No-op
Chris@16:     ///
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return ch
Chris@16:     static char_type translate(char_type ch)
Chris@16:     {
Chris@16:         return ch;
Chris@16:     }
Chris@16: 
Chris@16:     /// No-op
Chris@16:     ///
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return ch
Chris@16:     static char_type translate_nocase(char_type ch)
Chris@16:     {
Chris@16:         return ch;
Chris@16:     }
Chris@16: 
Chris@16:     /// Checks to see if a character is within a character range.
Chris@16:     ///
Chris@16:     /// \param first The bottom of the range, inclusive.
Chris@16:     /// \param last The top of the range, inclusive.
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return first <= ch && ch <= last.
Chris@16:     static bool in_range(char_type first, char_type last, char_type ch)
Chris@16:     {
Chris@16:         return first <= ch && ch <= last;
Chris@16:     }
Chris@16: 
Chris@16:     /// Checks to see if a character is within a character range.
Chris@16:     ///
Chris@16:     /// \param first The bottom of the range, inclusive.
Chris@16:     /// \param last The top of the range, inclusive.
Chris@16:     /// \param ch The source character.
Chris@16:     /// \return first <= ch && ch <= last.
Chris@16:     /// \attention Since the null_regex_traits does not do case-folding,
Chris@16:     /// this function is equivalent to in_range().
Chris@16:     static bool in_range_nocase(char_type first, char_type last, char_type ch)
Chris@16:     {
Chris@16:         return first <= ch && ch <= last;
Chris@16:     }
Chris@16: 
Chris@16:     /// Returns a sort key for the character sequence designated by the iterator range [F1, F2)
Chris@16:     /// such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2)
Chris@16:     /// then v.transform(G1, G2) < v.transform(H1, H2).
Chris@16:     ///
Chris@16:     /// \attention Not currently used
Chris@16:     template<typename FwdIter>
Chris@16:     static string_type transform(FwdIter begin, FwdIter end)
Chris@16:     {
Chris@16:         return string_type(begin, end);
Chris@16:     }
Chris@16: 
Chris@16:     /// Returns a sort key for the character sequence designated by the iterator range [F1, F2)
Chris@16:     /// such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2)
Chris@16:     /// when character case is not considered then
Chris@16:     /// v.transform_primary(G1, G2) < v.transform_primary(H1, H2).
Chris@16:     ///
Chris@16:     /// \attention Not currently used
Chris@16:     template<typename FwdIter>
Chris@16:     static string_type transform_primary(FwdIter begin, FwdIter end)
Chris@16:     {
Chris@16:         return string_type(begin, end);
Chris@16:     }
Chris@16: 
Chris@16:     /// Returns a sequence of characters that represents the collating element
Chris@16:     /// consisting of the character sequence designated by the iterator range [F1, F2).
Chris@16:     /// Returns an empty string if the character sequence is not a valid collating element.
Chris@16:     ///
Chris@16:     /// \attention Not currently used
Chris@16:     template<typename FwdIter>
Chris@16:     static string_type lookup_collatename(FwdIter begin, FwdIter end)
Chris@16:     {
Chris@16:         detail::ignore_unused(begin);
Chris@16:         detail::ignore_unused(end);
Chris@16:         return string_type();
Chris@16:     }
Chris@16: 
Chris@16:     /// The null_regex_traits does not have character classifications, so lookup_classname()
Chris@16:     /// is unused.
Chris@16:     ///
Chris@16:     /// \param begin not used
Chris@16:     /// \param end not used
Chris@16:     /// \param icase not used
Chris@16:     /// \return static_cast\<char_class_type\>(0)
Chris@16:     template<typename FwdIter>
Chris@16:     static char_class_type lookup_classname(FwdIter begin, FwdIter end, bool icase)
Chris@16:     {
Chris@16:         detail::ignore_unused(begin);
Chris@16:         detail::ignore_unused(end);
Chris@16:         detail::ignore_unused(icase);
Chris@16:         return 0;
Chris@16:     }
Chris@16: 
Chris@16:     /// The null_regex_traits does not have character classifications, so isctype()
Chris@16:     /// is unused.
Chris@16:     ///
Chris@16:     /// \param ch not used
Chris@16:     /// \param mask not used
Chris@16:     /// \return false
Chris@16:     static bool isctype(char_type ch, char_class_type mask)
Chris@16:     {
Chris@16:         detail::ignore_unused(ch);
Chris@16:         detail::ignore_unused(mask);
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     /// The null_regex_traits recognizes no elements as digits, so value() is unused.
Chris@16:     ///
Chris@16:     /// \param ch not used
Chris@16:     /// \param radix not used
Chris@16:     /// \return -1
Chris@16:     static int value(char_type ch, int radix)
Chris@16:     {
Chris@16:         detail::ignore_unused(ch);
Chris@16:         detail::ignore_unused(radix);
Chris@16:         return -1;
Chris@16:     }
Chris@16: 
Chris@16:     /// Not used
Chris@16:     ///
Chris@16:     /// \param loc not used
Chris@16:     /// \return loc
Chris@16:     static locale_type imbue(locale_type loc)
Chris@16:     {
Chris@16:         return loc;
Chris@16:     }
Chris@16: 
Chris@16:     /// Returns locale_type().
Chris@16:     ///
Chris@16:     /// \return locale_type()
Chris@16:     static locale_type getloc()
Chris@16:     {
Chris@16:         return locale_type();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: #endif