123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231 |
- ///////////////////////////////////////////////////////////////////////////////
- /// \file null_regex_traits.hpp
- /// Contains the definition of the null_regex_traits\<\> template, which is a
- /// stub regex traits implementation that can be used by static and dynamic
- /// regexes for searching non-character data.
- //
- // Copyright 2008 Eric Niebler. 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)
- #ifndef BOOST_XPRESSIVE_TRAITS_NULL_REGEX_TRAITS_HPP_EAN_10_04_2005
- #define BOOST_XPRESSIVE_TRAITS_NULL_REGEX_TRAITS_HPP_EAN_10_04_2005
- // MS compatible compilers support #pragma once
- #if defined(_MSC_VER)
- # pragma once
- #endif
- #include <vector>
- #include <boost/assert.hpp>
- #include <boost/mpl/assert.hpp>
- #include <boost/xpressive/detail/detail_fwd.hpp>
- #include <boost/xpressive/detail/utility/never_true.hpp>
- #include <boost/xpressive/detail/utility/ignore_unused.hpp>
- namespace boost { namespace xpressive
- {
- namespace detail
- {
- struct not_a_locale {};
- }
- struct regex_traits_version_1_tag;
- ///////////////////////////////////////////////////////////////////////////////
- // null_regex_traits
- //
- /// \brief stub regex_traits for non-char data
- ///
- template<typename Elem>
- struct null_regex_traits
- {
- typedef Elem char_type;
- typedef std::vector<char_type> string_type;
- typedef detail::not_a_locale locale_type;
- typedef int char_class_type;
- typedef regex_traits_version_1_tag version_tag;
- /// Initialize a null_regex_traits object.
- ///
- null_regex_traits(locale_type = locale_type())
- {
- }
- /// Checks two null_regex_traits objects for equality
- ///
- /// \return true.
- bool operator ==(null_regex_traits<char_type> const &that) const
- {
- detail::ignore_unused(that);
- return true;
- }
- /// Checks two null_regex_traits objects for inequality
- ///
- /// \return false.
- bool operator !=(null_regex_traits<char_type> const &that) const
- {
- detail::ignore_unused(that);
- return false;
- }
- /// Convert a char to a Elem
- ///
- /// \param ch The source character.
- /// \return Elem(ch).
- char_type widen(char ch) const
- {
- return char_type(ch);
- }
- /// Returns a hash value for a Elem in the range [0, UCHAR_MAX]
- ///
- /// \param ch The source character.
- /// \return a value between 0 and UCHAR_MAX, inclusive.
- static unsigned char hash(char_type ch)
- {
- return static_cast<unsigned char>(ch);
- }
- /// No-op
- ///
- /// \param ch The source character.
- /// \return ch
- static char_type translate(char_type ch)
- {
- return ch;
- }
- /// No-op
- ///
- /// \param ch The source character.
- /// \return ch
- static char_type translate_nocase(char_type ch)
- {
- return ch;
- }
- /// Checks to see if a character is within a character range.
- ///
- /// \param first The bottom of the range, inclusive.
- /// \param last The top of the range, inclusive.
- /// \param ch The source character.
- /// \return first <= ch && ch <= last.
- static bool in_range(char_type first, char_type last, char_type ch)
- {
- return first <= ch && ch <= last;
- }
- /// Checks to see if a character is within a character range.
- ///
- /// \param first The bottom of the range, inclusive.
- /// \param last The top of the range, inclusive.
- /// \param ch The source character.
- /// \return first <= ch && ch <= last.
- /// \attention Since the null_regex_traits does not do case-folding,
- /// this function is equivalent to in_range().
- static bool in_range_nocase(char_type first, char_type last, char_type ch)
- {
- return first <= ch && ch <= last;
- }
- /// Returns a sort key for the character sequence designated by the iterator range [F1, F2)
- /// such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2)
- /// then v.transform(G1, G2) < v.transform(H1, H2).
- ///
- /// \attention Not currently used
- template<typename FwdIter>
- static string_type transform(FwdIter begin, FwdIter end)
- {
- return string_type(begin, end);
- }
- /// Returns a sort key for the character sequence designated by the iterator range [F1, F2)
- /// such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2)
- /// when character case is not considered then
- /// v.transform_primary(G1, G2) < v.transform_primary(H1, H2).
- ///
- /// \attention Not currently used
- template<typename FwdIter>
- static string_type transform_primary(FwdIter begin, FwdIter end)
- {
- return string_type(begin, end);
- }
- /// Returns a sequence of characters that represents the collating element
- /// consisting of the character sequence designated by the iterator range [F1, F2).
- /// Returns an empty string if the character sequence is not a valid collating element.
- ///
- /// \attention Not currently used
- template<typename FwdIter>
- static string_type lookup_collatename(FwdIter begin, FwdIter end)
- {
- detail::ignore_unused(begin);
- detail::ignore_unused(end);
- return string_type();
- }
- /// The null_regex_traits does not have character classifications, so lookup_classname()
- /// is unused.
- ///
- /// \param begin not used
- /// \param end not used
- /// \param icase not used
- /// \return static_cast\<char_class_type\>(0)
- template<typename FwdIter>
- static char_class_type lookup_classname(FwdIter begin, FwdIter end, bool icase)
- {
- detail::ignore_unused(begin);
- detail::ignore_unused(end);
- detail::ignore_unused(icase);
- return 0;
- }
- /// The null_regex_traits does not have character classifications, so isctype()
- /// is unused.
- ///
- /// \param ch not used
- /// \param mask not used
- /// \return false
- static bool isctype(char_type ch, char_class_type mask)
- {
- detail::ignore_unused(ch);
- detail::ignore_unused(mask);
- return false;
- }
- /// The null_regex_traits recognizes no elements as digits, so value() is unused.
- ///
- /// \param ch not used
- /// \param radix not used
- /// \return -1
- static int value(char_type ch, int radix)
- {
- detail::ignore_unused(ch);
- detail::ignore_unused(radix);
- return -1;
- }
- /// Not used
- ///
- /// \param loc not used
- /// \return loc
- static locale_type imbue(locale_type loc)
- {
- return loc;
- }
- /// Returns locale_type().
- ///
- /// \return locale_type()
- static locale_type getloc()
- {
- return locale_type();
- }
- };
- }}
- #endif
|