[29] | 1 | #ifndef POINTEE_DWA200415_HPP |
---|
| 2 | # define POINTEE_DWA200415_HPP |
---|
| 3 | |
---|
| 4 | // |
---|
| 5 | // Copyright David Abrahams 2004. Use, modification and distribution is |
---|
| 6 | // subject to the Boost Software License, Version 1.0. (See accompanying |
---|
| 7 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
---|
| 8 | // |
---|
| 9 | // typename pointee<P>::type provides the pointee type of P. |
---|
| 10 | // |
---|
| 11 | // For example, it is T for T* and X for shared_ptr<X>. |
---|
| 12 | // |
---|
| 13 | // http://www.boost.org/libs/iterator/doc/pointee.html |
---|
| 14 | // |
---|
| 15 | |
---|
| 16 | # include <boost/detail/is_incrementable.hpp> |
---|
| 17 | # include <boost/iterator/iterator_traits.hpp> |
---|
| 18 | # include <boost/type_traits/add_const.hpp> |
---|
| 19 | # include <boost/type_traits/remove_cv.hpp> |
---|
| 20 | # include <boost/mpl/if.hpp> |
---|
| 21 | # include <boost/mpl/eval_if.hpp> |
---|
| 22 | |
---|
| 23 | namespace boost { |
---|
| 24 | |
---|
| 25 | namespace detail |
---|
| 26 | { |
---|
| 27 | template <class P> |
---|
| 28 | struct smart_ptr_pointee |
---|
| 29 | { |
---|
| 30 | typedef typename P::element_type type; |
---|
| 31 | }; |
---|
| 32 | |
---|
| 33 | template <class Iterator> |
---|
| 34 | struct iterator_pointee |
---|
| 35 | { |
---|
| 36 | typedef typename iterator_traits<Iterator>::value_type value_type; |
---|
| 37 | |
---|
| 38 | struct impl |
---|
| 39 | { |
---|
| 40 | template <class T> |
---|
| 41 | static char test(T const&); |
---|
| 42 | |
---|
| 43 | static char (& test(value_type&) )[2]; |
---|
| 44 | |
---|
| 45 | static Iterator& x; |
---|
| 46 | }; |
---|
| 47 | |
---|
| 48 | BOOST_STATIC_CONSTANT(bool, is_constant = sizeof(impl::test(*impl::x)) == 1); |
---|
| 49 | |
---|
| 50 | typedef typename mpl::if_c< |
---|
| 51 | # if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551)) |
---|
| 52 | ::boost::detail::iterator_pointee<Iterator>::is_constant |
---|
| 53 | # else |
---|
| 54 | is_constant |
---|
| 55 | # endif |
---|
| 56 | , typename add_const<value_type>::type |
---|
| 57 | , value_type |
---|
| 58 | >::type type; |
---|
| 59 | }; |
---|
| 60 | } |
---|
| 61 | |
---|
| 62 | template <class P> |
---|
| 63 | struct pointee |
---|
| 64 | : mpl::eval_if< |
---|
| 65 | detail::is_incrementable<P> |
---|
| 66 | , detail::iterator_pointee<P> |
---|
| 67 | , detail::smart_ptr_pointee<P> |
---|
| 68 | > |
---|
| 69 | { |
---|
| 70 | }; |
---|
| 71 | |
---|
| 72 | } // namespace boost |
---|
| 73 | |
---|
| 74 | #endif // POINTEE_DWA200415_HPP |
---|