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Diffstat (limited to 'cutl/details/boost/iterator/iterator_categories.hpp')
| -rw-r--r-- | cutl/details/boost/iterator/iterator_categories.hpp | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/cutl/details/boost/iterator/iterator_categories.hpp b/cutl/details/boost/iterator/iterator_categories.hpp new file mode 100644 index 0000000..cf22031 --- /dev/null +++ b/cutl/details/boost/iterator/iterator_categories.hpp @@ -0,0 +1,188 @@ +// (C) Copyright Jeremy Siek 2002. +// 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_ITERATOR_CATEGORIES_HPP +# define BOOST_ITERATOR_CATEGORIES_HPP + +# include <cutl/details/boost/config.hpp> +# include <cutl/details/boost/detail/iterator.hpp> +# include <cutl/details/boost/iterator/detail/config_def.hpp> + +# include <cutl/details/boost/detail/workaround.hpp> + +# include <cutl/details/boost/mpl/eval_if.hpp> +# include <cutl/details/boost/mpl/identity.hpp> +# include <cutl/details/boost/mpl/placeholders.hpp> +# include <cutl/details/boost/mpl/aux_/lambda_support.hpp> + +# include <cutl/details/boost/type_traits/is_convertible.hpp> + +# include <cutl/details/boost/static_assert.hpp> + +namespace cutl_details_boost { + +// +// Traversal Categories +// + +struct no_traversal_tag {}; + +struct incrementable_traversal_tag + : no_traversal_tag +{ +// incrementable_traversal_tag() {} +// incrementable_traversal_tag(std::output_iterator_tag const&) {}; +}; + +struct single_pass_traversal_tag + : incrementable_traversal_tag +{ +// single_pass_traversal_tag() {} +// single_pass_traversal_tag(std::input_iterator_tag const&) {}; +}; + +struct forward_traversal_tag + : single_pass_traversal_tag +{ +// forward_traversal_tag() {} +// forward_traversal_tag(std::forward_iterator_tag const&) {}; +}; + +struct bidirectional_traversal_tag + : forward_traversal_tag +{ +// bidirectional_traversal_tag() {}; +// bidirectional_traversal_tag(std::bidirectional_iterator_tag const&) {}; +}; + +struct random_access_traversal_tag + : bidirectional_traversal_tag +{ +// random_access_traversal_tag() {}; +// random_access_traversal_tag(std::random_access_iterator_tag const&) {}; +}; + +namespace detail +{ + // + // Convert a "strictly old-style" iterator category to a traversal + // tag. This is broken out into a separate metafunction to reduce + // the cost of instantiating iterator_category_to_traversal, below, + // for new-style types. + // + template <class Cat> + struct old_category_to_traversal + : mpl::eval_if< + is_convertible<Cat,std::random_access_iterator_tag> + , mpl::identity<random_access_traversal_tag> + , mpl::eval_if< + is_convertible<Cat,std::bidirectional_iterator_tag> + , mpl::identity<bidirectional_traversal_tag> + , mpl::eval_if< + is_convertible<Cat,std::forward_iterator_tag> + , mpl::identity<forward_traversal_tag> + , mpl::eval_if< + is_convertible<Cat,std::input_iterator_tag> + , mpl::identity<single_pass_traversal_tag> + , mpl::eval_if< + is_convertible<Cat,std::output_iterator_tag> + , mpl::identity<incrementable_traversal_tag> + , void + > + > + > + > + > + {}; + +# if BOOST_WORKAROUND(BOOST_MSVC, < 1300) + template <> + struct old_category_to_traversal<int> + { + typedef int type; + }; +# endif + + template <class Traversal> + struct pure_traversal_tag + : mpl::eval_if< + is_convertible<Traversal,random_access_traversal_tag> + , mpl::identity<random_access_traversal_tag> + , mpl::eval_if< + is_convertible<Traversal,bidirectional_traversal_tag> + , mpl::identity<bidirectional_traversal_tag> + , mpl::eval_if< + is_convertible<Traversal,forward_traversal_tag> + , mpl::identity<forward_traversal_tag> + , mpl::eval_if< + is_convertible<Traversal,single_pass_traversal_tag> + , mpl::identity<single_pass_traversal_tag> + , mpl::eval_if< + is_convertible<Traversal,incrementable_traversal_tag> + , mpl::identity<incrementable_traversal_tag> + , void + > + > + > + > + > + { + }; + +# if BOOST_WORKAROUND(BOOST_MSVC, < 1300) + template <> + struct pure_traversal_tag<int> + { + typedef int type; + }; +# endif + +} // namespace detail + + +// +// Convert an iterator category into a traversal tag +// +template <class Cat> +struct iterator_category_to_traversal + : mpl::eval_if< // if already convertible to a traversal tag, we're done. + is_convertible<Cat,incrementable_traversal_tag> + , mpl::identity<Cat> + , cutl_details_boost::detail::old_category_to_traversal<Cat> + > +{}; + +// Trait to get an iterator's traversal category +template <class Iterator = mpl::_1> +struct iterator_traversal + : iterator_category_to_traversal< + typename cutl_details_boost::detail::iterator_traits<Iterator>::iterator_category + > +{}; + +# ifdef BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT +// Hack because BOOST_MPL_AUX_LAMBDA_SUPPORT doesn't seem to work +// out well. Instantiating the nested apply template also +// requires instantiating iterator_traits on the +// placeholder. Instead we just specialize it as a metafunction +// class. +template <> +struct iterator_traversal<mpl::_1> +{ + template <class T> + struct apply : iterator_traversal<T> + {}; +}; +template <> +struct iterator_traversal<mpl::_> + : iterator_traversal<mpl::_1> +{}; +# endif + +} // namespace cutl_details_boost + +#include <cutl/details/boost/iterator/detail/config_undef.hpp> + +#endif // BOOST_ITERATOR_CATEGORIES_HPP |