123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100 |
- /*=============================================================================
- Copyright (c) 2001-2014 Joel de Guzman
- 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_SKIP_APRIL_16_2006_0625PM)
- #define BOOST_SPIRIT_X3_SKIP_APRIL_16_2006_0625PM
- #include <boost/spirit/home/x3/support/unused.hpp>
- #include <boost/spirit/home/x3/support/context.hpp>
- #include <boost/spirit/home/x3/support/traits/attribute_category.hpp>
- #include <boost/mpl/bool.hpp>
- #include <boost/mpl/not.hpp>
- #include <boost/type_traits/remove_cv.hpp>
- #include <boost/type_traits/remove_reference.hpp>
- #include <boost/utility/declval.hpp>
- namespace boost { namespace spirit { namespace x3
- {
- ///////////////////////////////////////////////////////////////////////////
- // Move the /first/ iterator to the first non-matching position
- // given a skip-parser. The function is a no-op if unused_type or
- // unused_skipper is passed as the skip-parser.
- ///////////////////////////////////////////////////////////////////////////
- template <typename Skipper>
- struct unused_skipper : unused_type
- {
- unused_skipper(Skipper const& skipper)
- : skipper(skipper) {}
- Skipper const& skipper;
- };
- namespace detail
- {
- template <typename Skipper>
- struct is_unused_skipper
- : mpl::false_ {};
- template <typename Skipper>
- struct is_unused_skipper<unused_skipper<Skipper>>
- : mpl::true_ {};
- template <>
- struct is_unused_skipper<unused_type>
- : mpl::true_ {};
- template <typename Skipper>
- inline Skipper const&
- get_unused_skipper(Skipper const& skipper)
- {
- return skipper;
- }
- template <typename Skipper>
- inline Skipper const&
- get_unused_skipper(unused_skipper<Skipper> const& unused_skipper)
- {
- return unused_skipper.skipper;
- }
- template <typename Iterator, typename Skipper>
- inline void skip_over(
- Iterator& first, Iterator const& last, Skipper const& skipper)
- {
- while (skipper.parse(first, last, unused, unused, unused))
- /***/;
- }
- template <typename Iterator>
- inline void skip_over(Iterator&, Iterator const&, unused_type)
- {
- }
- template <typename Iterator, typename Skipper>
- inline void skip_over(
- Iterator&, Iterator const&, unused_skipper<Skipper> const&)
- {
- }
- }
- // this tag is used to find the skipper from the context
- struct skipper_tag;
-
- template <typename Context>
- struct has_skipper
- : mpl::not_<detail::is_unused_skipper<
- typename remove_cv<typename remove_reference<
- decltype(x3::get<skipper_tag>(boost::declval<Context>()))
- >::type>::type
- >> {};
- template <typename Iterator, typename Context>
- inline void skip_over(
- Iterator& first, Iterator const& last, Context const& context)
- {
- detail::skip_over(first, last, x3::get<skipper_tag>(context));
- }
- }}}
- #endif
|