/* Copyright 2016 Joaquin M Lopez Munoz.
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* Distributed under the Boost Software License, Version 1.0.
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* (See accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*
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* See http://www.boost.org/libs/poly_collection for library home page.
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*/
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#ifndef BOOST_POLY_COLLECTION_DETAIL_ANY_ITERATOR_HPP
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#define BOOST_POLY_COLLECTION_DETAIL_ANY_ITERATOR_HPP
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#if defined(_MSC_VER)
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#pragma once
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#endif
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#include <boost/iterator/iterator_adaptor.hpp>
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#include <boost/type_erasure/any_cast.hpp>
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#include <type_traits>
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#include <utility>
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namespace boost{
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namespace poly_collection{
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namespace detail{
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/* type_erasure::any<Concept>* adaptor convertible to pointer to wrapped
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* entity.
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*/
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template<typename Any>
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class any_iterator:public boost::iterator_adaptor<any_iterator<Any>,Any*>
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{
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public:
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any_iterator()=default;
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explicit any_iterator(Any* p)noexcept:any_iterator::iterator_adaptor_{p}{}
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any_iterator(const any_iterator&)=default;
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any_iterator& operator=(const any_iterator&)=default;
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template<
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typename NonConstAny,
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typename std::enable_if<
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std::is_same<Any,const NonConstAny>::value>::type* =nullptr
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>
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any_iterator(const any_iterator<NonConstAny>& x)noexcept:
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any_iterator::iterator_adaptor_{x.base()}{}
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template<
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typename NonConstAny,
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typename std::enable_if<
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std::is_same<Any,const NonConstAny>::value>::type* =nullptr
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>
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any_iterator& operator=(const any_iterator<NonConstAny>& x)noexcept
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{
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this->base_reference()=x.base();
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return *this;
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}
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/* interoperability with Any* */
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any_iterator& operator=(Any* p)noexcept
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{this->base_reference()=p;return *this;}
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operator Any*()const noexcept{return this->base();}
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/* interoperability with Concrete* */
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template<
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typename Concrete,
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typename std::enable_if<
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/* can't compile-time check concept compliance */
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!std::is_const<Any>::value||std::is_const<Concrete>::value
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>::type* =nullptr
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>
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explicit operator Concrete*()const noexcept
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{
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return const_cast<Concrete*>(
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static_cast<typename std::remove_const<Concrete>::type*>(
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type_erasure::any_cast<void*>(this->base())));
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}
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private:
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template<typename>
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friend class any_iterator;
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};
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} /* namespace poly_collection::detail */
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} /* namespace poly_collection */
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} /* namespace boost */
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#endif
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