75 lines
1.8 KiB
C++
75 lines
1.8 KiB
C++
#ifndef POINTEE_DWA200415_HPP
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# define POINTEE_DWA200415_HPP
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//
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// Copyright David Abrahams 2004. Use, modification and distribution is
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// subject to the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// typename pointee<P>::type provides the pointee type of P.
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//
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// For example, it is T for T* and X for shared_ptr<X>.
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//
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// http://www.boost.org/libs/iterator/doc/pointee.html
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//
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# include <boost/detail/is_incrementable.hpp>
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# include <boost/iterator/iterator_traits.hpp>
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# include <boost/type_traits/add_const.hpp>
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# include <boost/type_traits/remove_cv.hpp>
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# include <boost/mpl/if.hpp>
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# include <boost/mpl/eval_if.hpp>
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namespace boost {
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namespace detail
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{
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template <class P>
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struct smart_ptr_pointee
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{
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typedef typename P::element_type type;
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};
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template <class Iterator>
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struct iterator_pointee
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{
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typedef typename iterator_traits<Iterator>::value_type value_type;
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struct impl
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{
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template <class T>
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static char test(T const&);
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static char (& test(value_type&) )[2];
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static Iterator& x;
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};
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BOOST_STATIC_CONSTANT(bool, is_constant = sizeof(impl::test(*impl::x)) == 1);
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typedef typename mpl::if_c<
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# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
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::boost::detail::iterator_pointee<Iterator>::is_constant
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# else
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is_constant
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# endif
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, typename add_const<value_type>::type
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, value_type
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>::type type;
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};
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}
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template <class P>
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struct pointee
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: mpl::eval_if<
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detail::is_incrementable<P>
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, detail::iterator_pointee<P>
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, detail::smart_ptr_pointee<P>
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>
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{
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};
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} // namespace boost
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#endif // POINTEE_DWA200415_HPP
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