diff options
Diffstat (limited to 'contrib/src/boost/iterator/detail/facade_iterator_category.hpp')
| -rw-r--r-- | contrib/src/boost/iterator/detail/facade_iterator_category.hpp | 386 |
1 files changed, 193 insertions, 193 deletions
diff --git a/contrib/src/boost/iterator/detail/facade_iterator_category.hpp b/contrib/src/boost/iterator/detail/facade_iterator_category.hpp index 73f5ff9..67fdf44 100644 --- a/contrib/src/boost/iterator/detail/facade_iterator_category.hpp +++ b/contrib/src/boost/iterator/detail/facade_iterator_category.hpp @@ -1,193 +1,193 @@ -// Copyright David Abrahams 2003. Use, modification and distribution is
-// subject to 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 FACADE_ITERATOR_CATEGORY_DWA20031118_HPP
-# define FACADE_ITERATOR_CATEGORY_DWA20031118_HPP
-
-# include <boost/iterator/iterator_categories.hpp>
-
-# include <boost/mpl/or.hpp> // used in iterator_tag inheritance logic
-# include <boost/mpl/and.hpp>
-# include <boost/mpl/if.hpp>
-# include <boost/mpl/eval_if.hpp>
-# include <boost/mpl/identity.hpp>
-# include <boost/mpl/assert.hpp>
-
-# include <boost/type_traits/is_same.hpp>
-# include <boost/type_traits/is_const.hpp>
-# include <boost/type_traits/is_reference.hpp>
-# include <boost/type_traits/is_convertible.hpp>
-
-# include <boost/type_traits/is_same.hpp>
-
-# include <boost/iterator/detail/config_def.hpp> // try to keep this last
-
-# ifdef BOOST_ITERATOR_REF_CONSTNESS_KILLS_WRITABILITY
-# include <boost/detail/indirect_traits.hpp>
-# endif
-
-//
-// iterator_category deduction for iterator_facade
-//
-
-namespace boost {
-namespace iterators {
-
-// forward declaration
-struct use_default;
-
-namespace detail {
-
-struct input_output_iterator_tag
- : std::input_iterator_tag
-{
- // Using inheritance for only input_iterator_tag helps to avoid
- // ambiguities when a stdlib implementation dispatches on a
- // function which is overloaded on both input_iterator_tag and
- // output_iterator_tag, as STLPort does, in its __valid_range
- // function. I claim it's better to avoid the ambiguity in these
- // cases.
- operator std::output_iterator_tag() const
- {
- return std::output_iterator_tag();
- }
-};
-
-//
-// True iff the user has explicitly disabled writability of this
-// iterator. Pass the iterator_facade's Value parameter and its
-// nested ::reference type.
-//
-template <class ValueParam, class Reference>
-struct iterator_writability_disabled
-# ifdef BOOST_ITERATOR_REF_CONSTNESS_KILLS_WRITABILITY // Adding Thomas' logic?
- : mpl::or_<
- is_const<Reference>
- , boost::detail::indirect_traits::is_reference_to_const<Reference>
- , is_const<ValueParam>
- >
-# else
- : is_const<ValueParam>
-# endif
-{};
-
-
-//
-// Convert an iterator_facade's traversal category, Value parameter,
-// and ::reference type to an appropriate old-style category.
-//
-// Due to changeset 21683, this now never results in a category convertible
-// to output_iterator_tag.
-//
-// Change at: https://svn.boost.org/trac/boost/changeset/21683
-template <class Traversal, class ValueParam, class Reference>
-struct iterator_facade_default_category
- : mpl::eval_if<
- mpl::and_<
- is_reference<Reference>
- , is_convertible<Traversal,forward_traversal_tag>
- >
- , mpl::eval_if<
- is_convertible<Traversal,random_access_traversal_tag>
- , mpl::identity<std::random_access_iterator_tag>
- , mpl::if_<
- is_convertible<Traversal,bidirectional_traversal_tag>
- , std::bidirectional_iterator_tag
- , std::forward_iterator_tag
- >
- >
- , typename mpl::eval_if<
- mpl::and_<
- is_convertible<Traversal, single_pass_traversal_tag>
-
- // check for readability
- , is_convertible<Reference, ValueParam>
- >
- , mpl::identity<std::input_iterator_tag>
- , mpl::identity<Traversal>
- >
- >
-{
-};
-
-// True iff T is convertible to an old-style iterator category.
-template <class T>
-struct is_iterator_category
- : mpl::or_<
- is_convertible<T,std::input_iterator_tag>
- , is_convertible<T,std::output_iterator_tag>
- >
-{
-};
-
-template <class T>
-struct is_iterator_traversal
- : is_convertible<T,incrementable_traversal_tag>
-{};
-
-//
-// A composite iterator_category tag convertible to Category (a pure
-// old-style category) and Traversal (a pure traversal tag).
-// Traversal must be a strict increase of the traversal power given by
-// Category.
-//
-template <class Category, class Traversal>
-struct iterator_category_with_traversal
- : Category, Traversal
-{
- // Make sure this isn't used to build any categories where
- // convertibility to Traversal is redundant. Should just use the
- // Category element in that case.
- BOOST_MPL_ASSERT_NOT((
- is_convertible<
- typename iterator_category_to_traversal<Category>::type
- , Traversal
- >));
-
- BOOST_MPL_ASSERT((is_iterator_category<Category>));
- BOOST_MPL_ASSERT_NOT((is_iterator_category<Traversal>));
- BOOST_MPL_ASSERT_NOT((is_iterator_traversal<Category>));
-# if !BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1310))
- BOOST_MPL_ASSERT((is_iterator_traversal<Traversal>));
-# endif
-};
-
-// Computes an iterator_category tag whose traversal is Traversal and
-// which is appropriate for an iterator
-template <class Traversal, class ValueParam, class Reference>
-struct facade_iterator_category_impl
-{
- BOOST_MPL_ASSERT_NOT((is_iterator_category<Traversal>));
-
- typedef typename iterator_facade_default_category<
- Traversal,ValueParam,Reference
- >::type category;
-
- typedef typename mpl::if_<
- is_same<
- Traversal
- , typename iterator_category_to_traversal<category>::type
- >
- , category
- , iterator_category_with_traversal<category,Traversal>
- >::type type;
-};
-
-//
-// Compute an iterator_category for iterator_facade
-//
-template <class CategoryOrTraversal, class ValueParam, class Reference>
-struct facade_iterator_category
- : mpl::eval_if<
- is_iterator_category<CategoryOrTraversal>
- , mpl::identity<CategoryOrTraversal> // old-style categories are fine as-is
- , facade_iterator_category_impl<CategoryOrTraversal,ValueParam,Reference>
- >
-{
-};
-
-}}} // namespace boost::iterators::detail
-
-# include <boost/iterator/detail/config_undef.hpp>
-
-#endif // FACADE_ITERATOR_CATEGORY_DWA20031118_HPP
+// Copyright David Abrahams 2003. Use, modification and distribution is +// subject to 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 FACADE_ITERATOR_CATEGORY_DWA20031118_HPP +# define FACADE_ITERATOR_CATEGORY_DWA20031118_HPP + +# include <boost/iterator/iterator_categories.hpp> + +# include <boost/mpl/or.hpp> // used in iterator_tag inheritance logic +# include <boost/mpl/and.hpp> +# include <boost/mpl/if.hpp> +# include <boost/mpl/eval_if.hpp> +# include <boost/mpl/identity.hpp> +# include <boost/mpl/assert.hpp> + +# include <boost/type_traits/is_same.hpp> +# include <boost/type_traits/is_const.hpp> +# include <boost/type_traits/is_reference.hpp> +# include <boost/type_traits/is_convertible.hpp> + +# include <boost/type_traits/is_same.hpp> + +# include <boost/iterator/detail/config_def.hpp> // try to keep this last + +# ifdef BOOST_ITERATOR_REF_CONSTNESS_KILLS_WRITABILITY +# include <boost/detail/indirect_traits.hpp> +# endif + +// +// iterator_category deduction for iterator_facade +// + +namespace boost { +namespace iterators { + +// forward declaration +struct use_default; + +namespace detail { + +struct input_output_iterator_tag + : std::input_iterator_tag +{ + // Using inheritance for only input_iterator_tag helps to avoid + // ambiguities when a stdlib implementation dispatches on a + // function which is overloaded on both input_iterator_tag and + // output_iterator_tag, as STLPort does, in its __valid_range + // function. I claim it's better to avoid the ambiguity in these + // cases. + operator std::output_iterator_tag() const + { + return std::output_iterator_tag(); + } +}; + +// +// True iff the user has explicitly disabled writability of this +// iterator. Pass the iterator_facade's Value parameter and its +// nested ::reference type. +// +template <class ValueParam, class Reference> +struct iterator_writability_disabled +# ifdef BOOST_ITERATOR_REF_CONSTNESS_KILLS_WRITABILITY // Adding Thomas' logic? + : mpl::or_< + is_const<Reference> + , boost::detail::indirect_traits::is_reference_to_const<Reference> + , is_const<ValueParam> + > +# else + : is_const<ValueParam> +# endif +{}; + + +// +// Convert an iterator_facade's traversal category, Value parameter, +// and ::reference type to an appropriate old-style category. +// +// Due to changeset 21683, this now never results in a category convertible +// to output_iterator_tag. +// +// Change at: https://svn.boost.org/trac/boost/changeset/21683 +template <class Traversal, class ValueParam, class Reference> +struct iterator_facade_default_category + : mpl::eval_if< + mpl::and_< + is_reference<Reference> + , is_convertible<Traversal,forward_traversal_tag> + > + , mpl::eval_if< + is_convertible<Traversal,random_access_traversal_tag> + , mpl::identity<std::random_access_iterator_tag> + , mpl::if_< + is_convertible<Traversal,bidirectional_traversal_tag> + , std::bidirectional_iterator_tag + , std::forward_iterator_tag + > + > + , typename mpl::eval_if< + mpl::and_< + is_convertible<Traversal, single_pass_traversal_tag> + + // check for readability + , is_convertible<Reference, ValueParam> + > + , mpl::identity<std::input_iterator_tag> + , mpl::identity<Traversal> + > + > +{ +}; + +// True iff T is convertible to an old-style iterator category. +template <class T> +struct is_iterator_category + : mpl::or_< + is_convertible<T,std::input_iterator_tag> + , is_convertible<T,std::output_iterator_tag> + > +{ +}; + +template <class T> +struct is_iterator_traversal + : is_convertible<T,incrementable_traversal_tag> +{}; + +// +// A composite iterator_category tag convertible to Category (a pure +// old-style category) and Traversal (a pure traversal tag). +// Traversal must be a strict increase of the traversal power given by +// Category. +// +template <class Category, class Traversal> +struct iterator_category_with_traversal + : Category, Traversal +{ + // Make sure this isn't used to build any categories where + // convertibility to Traversal is redundant. Should just use the + // Category element in that case. + BOOST_MPL_ASSERT_NOT(( + is_convertible< + typename iterator_category_to_traversal<Category>::type + , Traversal + >)); + + BOOST_MPL_ASSERT((is_iterator_category<Category>)); + BOOST_MPL_ASSERT_NOT((is_iterator_category<Traversal>)); + BOOST_MPL_ASSERT_NOT((is_iterator_traversal<Category>)); +# if !BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1310)) + BOOST_MPL_ASSERT((is_iterator_traversal<Traversal>)); +# endif +}; + +// Computes an iterator_category tag whose traversal is Traversal and +// which is appropriate for an iterator +template <class Traversal, class ValueParam, class Reference> +struct facade_iterator_category_impl +{ + BOOST_MPL_ASSERT_NOT((is_iterator_category<Traversal>)); + + typedef typename iterator_facade_default_category< + Traversal,ValueParam,Reference + >::type category; + + typedef typename mpl::if_< + is_same< + Traversal + , typename iterator_category_to_traversal<category>::type + > + , category + , iterator_category_with_traversal<category,Traversal> + >::type type; +}; + +// +// Compute an iterator_category for iterator_facade +// +template <class CategoryOrTraversal, class ValueParam, class Reference> +struct facade_iterator_category + : mpl::eval_if< + is_iterator_category<CategoryOrTraversal> + , mpl::identity<CategoryOrTraversal> // old-style categories are fine as-is + , facade_iterator_category_impl<CategoryOrTraversal,ValueParam,Reference> + > +{ +}; + +}}} // namespace boost::iterators::detail + +# include <boost/iterator/detail/config_undef.hpp> + +#endif // FACADE_ITERATOR_CATEGORY_DWA20031118_HPP |