Chris@16: // (C) Copyright David Abrahams 2002.
Chris@16: // (C) Copyright Jeremy Siek    2002.
Chris@16: // (C) Copyright Thomas Witt    2002.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
Chris@16: #define BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
Chris@16: 
Chris@16: #include <boost/iterator.hpp>
Chris@16: #include <boost/iterator/detail/enable_if.hpp>
Chris@16: #include <boost/iterator/iterator_adaptor.hpp>
Chris@16: #include <boost/iterator/iterator_categories.hpp>
Chris@16: #include <boost/mpl/not.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/type_traits/function_traits.hpp>
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@16: #include <boost/type_traits/is_class.hpp>
Chris@16: #include <boost/type_traits/is_function.hpp>
Chris@16: #include <boost/type_traits/is_reference.hpp>
Chris@16: #include <boost/type_traits/remove_const.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: 
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1310))
Chris@16: # include <boost/type_traits/is_base_and_derived.hpp>
Chris@16: 
Chris@101: #endif
Chris@16: #include <boost/iterator/detail/config_def.hpp>
Chris@16: 
Chris@16: 
Chris@101: namespace boost {
Chris@101: namespace iterators {
Chris@101: 
Chris@16:   template <class UnaryFunction, class Iterator, class Reference = use_default, class Value = use_default>
Chris@16:   class transform_iterator;
Chris@16: 
Chris@101:   namespace detail
Chris@16:   {
Chris@16:     // Compute the iterator_adaptor instantiation to be used for transform_iterator
Chris@16:     template <class UnaryFunc, class Iterator, class Reference, class Value>
Chris@16:     struct transform_iterator_base
Chris@16:     {
Chris@16:      private:
Chris@16:         // By default, dereferencing the iterator yields the same as
Chris@16:         // the function.
Chris@16:         typedef typename ia_dflt_help<
Chris@16:             Reference
Chris@16:           , result_of<const UnaryFunc(typename std::iterator_traits<Iterator>::reference)>
Chris@16:         >::type reference;
Chris@16: 
Chris@16:         // To get the default for Value: remove any reference on the
Chris@16:         // result type, but retain any constness to signal
Chris@16:         // non-writability.  Note that if we adopt Thomas' suggestion
Chris@16:         // to key non-writability *only* on the Reference argument,
Chris@16:         // we'd need to strip constness here as well.
Chris@16:         typedef typename ia_dflt_help<
Chris@16:             Value
Chris@16:           , remove_reference<reference>
Chris@16:         >::type cv_value_type;
Chris@16: 
Chris@16:      public:
Chris@16:         typedef iterator_adaptor<
Chris@16:             transform_iterator<UnaryFunc, Iterator, Reference, Value>
Chris@16:           , Iterator
Chris@16:           , cv_value_type
Chris@16:           , use_default    // Leave the traversal category alone
Chris@16:           , reference
Chris@16:         > type;
Chris@16:     };
Chris@16:   }
Chris@16: 
Chris@16:   template <class UnaryFunc, class Iterator, class Reference, class Value>
Chris@16:   class transform_iterator
Chris@101:     : public boost::iterators::detail::transform_iterator_base<UnaryFunc, Iterator, Reference, Value>::type
Chris@16:   {
Chris@16:     typedef typename
Chris@101:     boost::iterators::detail::transform_iterator_base<UnaryFunc, Iterator, Reference, Value>::type
Chris@16:     super_t;
Chris@16: 
Chris@16:     friend class iterator_core_access;
Chris@16: 
Chris@16:   public:
Chris@16:     transform_iterator() { }
Chris@16: 
Chris@16:     transform_iterator(Iterator const& x, UnaryFunc f)
Chris@16:       : super_t(x), m_f(f) { }
Chris@16: 
Chris@16:     explicit transform_iterator(Iterator const& x)
Chris@16:       : super_t(x)
Chris@16:     {
Chris@16:         // Pro8 is a little too aggressive about instantiating the
Chris@16:         // body of this function.
Chris@16: #if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
Chris@16:         // don't provide this constructor if UnaryFunc is a
Chris@16:         // function pointer type, since it will be 0.  Too dangerous.
Chris@16:         BOOST_STATIC_ASSERT(is_class<UnaryFunc>::value);
Chris@101: #endif
Chris@16:     }
Chris@16: 
Chris@16:     template <
Chris@16:         class OtherUnaryFunction
Chris@16:       , class OtherIterator
Chris@16:       , class OtherReference
Chris@16:       , class OtherValue>
Chris@16:     transform_iterator(
Chris@16:          transform_iterator<OtherUnaryFunction, OtherIterator, OtherReference, OtherValue> const& t
Chris@16:        , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
Chris@16: #if !BOOST_WORKAROUND(BOOST_MSVC, == 1310)
Chris@16:        , typename enable_if_convertible<OtherUnaryFunction, UnaryFunc>::type* = 0
Chris@101: #endif
Chris@16:     )
Chris@16:       : super_t(t.base()), m_f(t.functor())
Chris@16:    {}
Chris@16: 
Chris@16:     UnaryFunc functor() const
Chris@16:       { return m_f; }
Chris@16: 
Chris@16:   private:
Chris@16:     typename super_t::reference dereference() const
Chris@16:     { return m_f(*this->base()); }
Chris@16: 
Chris@16:     // Probably should be the initial base class so it can be
Chris@16:     // optimized away via EBO if it is an empty class.
Chris@16:     UnaryFunc m_f;
Chris@16:   };
Chris@16: 
Chris@16:   template <class UnaryFunc, class Iterator>
Chris@101:   inline transform_iterator<UnaryFunc, Iterator>
Chris@16:   make_transform_iterator(Iterator it, UnaryFunc fun)
Chris@16:   {
Chris@16:       return transform_iterator<UnaryFunc, Iterator>(it, fun);
Chris@16:   }
Chris@16: 
Chris@16:   // Version which allows explicit specification of the UnaryFunc
Chris@16:   // type.
Chris@16:   //
Chris@16:   // This generator is not provided if UnaryFunc is a function
Chris@16:   // pointer type, because it's too dangerous: the default-constructed
Chris@16:   // function pointer in the iterator be 0, leading to a runtime
Chris@16:   // crash.
Chris@16:   template <class UnaryFunc, class Iterator>
Chris@101:   inline typename iterators::enable_if<
Chris@16:       is_class<UnaryFunc>   // We should probably find a cheaper test than is_class<>
Chris@16:     , transform_iterator<UnaryFunc, Iterator>
Chris@16:   >::type
Chris@16:   make_transform_iterator(Iterator it)
Chris@16:   {
Chris@16:       return transform_iterator<UnaryFunc, Iterator>(it, UnaryFunc());
Chris@16:   }
Chris@16: 
Chris@16: #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION ) && !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
Chris@16:   template <class Return, class Argument, class Iterator>
Chris@101:   inline transform_iterator< Return (*)(Argument), Iterator, Return>
Chris@16:   make_transform_iterator(Iterator it, Return (*fun)(Argument))
Chris@16:   {
Chris@16:     return transform_iterator<Return (*)(Argument), Iterator, Return>(it, fun);
Chris@16:   }
Chris@16: #endif
Chris@16: 
Chris@101: } // namespace iterators
Chris@101: 
Chris@101: using iterators::transform_iterator;
Chris@101: using iterators::make_transform_iterator;
Chris@101: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/iterator/detail/config_undef.hpp>
Chris@16: 
Chris@16: #endif // BOOST_TRANSFORM_ITERATOR_23022003THW_HPP