A scripted SQL query generation framework with IDE: SQLpp (v1.4)

#ifndef LUABIND_SHARED_PTR_POLICY_INCLUDED
#define LUABIND_SHARED_PTR_POLICY_INCLUDED

// Allows up/down-casts of boost::shared_ptr's.
// This is done by first casting the held pointer
// up to a base class, then dynamic_cast down
// this pointer to the element_type of the shared_ptr
// and finally construct a new shared_ptr with the
// new raw pointer. To stop the shared_ptr from
// deleting the held object, we supply a custom
// deleter functor that doesn't do anything.

#include <luabind/config.hpp>
#include <luabind/detail/policy.hpp>
#include <luabind/detail/implicit_cast.hpp>
#include <boost/shared_ptr.hpp>

namespace luabind { namespace detail 
{
	struct do_nothing_deleter
	{ 
		void operator()(const void*) const {} 
	};

	struct shared_ptr_converter
	{
		template<class T>
		boost::shared_ptr<T> apply(lua_State* L, by_value<boost::shared_ptr<T> >, int index)
		{
			object_rep* obj = static_cast<object_rep*>(lua_touserdata(L, index));
			assert((obj != 0) && "internal error, please report"); // internal error
			const class_rep* crep = obj->crep();

			T* ptr = static_cast<T*>(crep->convert_to(LUABIND_TYPEID(T), obj, 0));
			return boost::shared_ptr<T>(ptr, do_nothing_deleter());
		}

		template<class T>
		boost::shared_ptr<T> apply(lua_State* L, by_const_reference<boost::shared_ptr<T> >, int index)
		{ return apply(L, by_value<boost::shared_ptr<T> >(), index); }

		template<class T>
		static int match(lua_State* L, by_value<boost::shared_ptr<T> >, int index)
		{
			object_rep* obj = static_cast<object_rep*>(lua_touserdata(L, index));
			assert((obj != 0) && "internal error, please report"); // internal error
			const class_rep* crep = obj->crep();

			int d;
			return implicit_cast(obj->crep(), LUABIND_TYPEID(T), d);
		}

		template<class T>
		static int match(lua_State* L, by_const_reference<boost::shared_ptr<T> >, int index)
		{ return match(L, by_value<boost::shared_ptr<T> >(), index); }

		void converter_postcall(...) {}
		void converter_precall(...) {}
	};

	template<int N>
	struct shared_ptr_policy : conversion_policy<N>
	{
		static void precall(lua_State*, const index_map&) {}
		static void postcall(lua_State*, const index_map&) {}

		template<class T, class Direction>
		struct generate_converter
		{
			typedef shared_ptr_converter type;
		};
	};
}}

namespace luabind
{
	template<int N>
	detail::policy_cons<detail::shared_ptr_policy<N>, detail::null_type>
	shared_ptr_policy(boost::arg<N>) { return detail::policy_cons<detail::shared_ptr_policy<N>, detail::null_type>(); }
}

namespace luabind
{
	template<class T>
	T* get_pointer(boost::shared_ptr<T>& p) { return p.get(); }

	template<class A>
	boost::shared_ptr<const A>* get_const_holder(boost::shared_ptr<A>*)
	{
		return 0;
	}
}

#endif