整理

include/boost/iterator/shared_container_iterator.hpp

@@ -0,0 +1,117 @@
+// (C) Copyright Ronald Garcia 2002. Permission to copy, use, modify, sell and
+// distribute this software is granted provided this copyright notice appears
+// in all copies. This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+
+// See http://www.boost.org/libs/utility/shared_container_iterator.html for documentation.
+
+#ifndef BOOST_ITERATOR_SHARED_CONTAINER_ITERATOR_HPP_INCLUDED_
+#define BOOST_ITERATOR_SHARED_CONTAINER_ITERATOR_HPP_INCLUDED_
+
+#include <memory>
+#include <utility>
+#include <boost/iterator/iterator_adaptor.hpp>
+
+namespace boost {
+
+// For backward compatibility with boost::shared_ptr
+template< class T >
+class shared_ptr;
+
+namespace iterators {
+namespace detail {
+
+// Fake deleter that holds an instance of boost::shared_ptr and through it keeps the pointed object from deletion
+template< typename T >
+class shared_container_iterator_bsptr_holder
+{
+private:
+    boost::shared_ptr< T > m_ptr;
+
+public:
+    explicit shared_container_iterator_bsptr_holder(boost::shared_ptr< T > const& ptr) :
+        m_ptr(ptr)
+    {}
+
+    void operator()(T*) const noexcept {}
+};
+
+} // namespace detail
+
+template< typename Container >
+class shared_container_iterator :
+    public iterator_adaptor<
+        shared_container_iterator< Container >,
+        typename Container::iterator
+    >
+{
+private:
+    using super_t = iterator_adaptor<
+        shared_container_iterator< Container >,
+        typename Container::iterator
+    >;
+
+    using iterator_t = typename Container::iterator;
+    using container_ref_t = std::shared_ptr< Container >;
+
+public:
+    shared_container_iterator() = default;
+
+    shared_container_iterator(iterator_t const& x, container_ref_t const& c) :
+        super_t(x),
+        m_container_ref(c)
+    {}
+
+    // Constructor for backward compatibility with boost::shared_ptr
+    shared_container_iterator(iterator_t const& x, boost::shared_ptr< Container > const& c) :
+        super_t(x),
+        m_container_ref(c.get(), detail::shared_container_iterator_bsptr_holder< Container >(c))
+    {}
+
+private:
+    container_ref_t m_container_ref;
+};
+
+template< typename Container >
+inline shared_container_iterator< Container >
+make_shared_container_iterator(typename Container::iterator iter, std::shared_ptr< Container > const& container)
+{
+    return shared_container_iterator< Container >(iter, container);
+}
+
+template< typename Container >
+inline std::pair< shared_container_iterator< Container >, shared_container_iterator< Container > >
+make_shared_container_range(std::shared_ptr< Container > const& container)
+{
+    return std::make_pair
+    (
+        iterators::make_shared_container_iterator(container->begin(), container),
+        iterators::make_shared_container_iterator(container->end(), container)
+    );
+}
+
+// Factory functions for backward compatibility with boost::shared_ptr
+template< typename Container >
+inline shared_container_iterator< Container >
+make_shared_container_iterator(typename Container::iterator iter, boost::shared_ptr< Container > const& container)
+{
+    return shared_container_iterator< Container >(iter, container);
+}
+
+template< typename Container >
+inline std::pair< shared_container_iterator< Container >, shared_container_iterator< Container > >
+make_shared_container_range(boost::shared_ptr< Container > const& container)
+{
+    std::shared_ptr< Container > c(container.get(), detail::shared_container_iterator_bsptr_holder< Container >(container));
+    return iterators::make_shared_container_range(std::move(c));
+}
+
+} // namespace iterators
+
+using iterators::shared_container_iterator;
+using iterators::make_shared_container_iterator;
+using iterators::make_shared_container_range;
+
+} // namespace boost
+
+#endif // BOOST_ITERATOR_SHARED_CONTAINER_ITERATOR_HPP_INCLUDED_