First working prototype

1 files changed, 127 insertions, 0 deletions

diff --git a/fusion_static_dispatch.hpp b/fusion_static_dispatch.hpp
new file mode 100644
index 0000000..17b6ff4
--- /dev/null
+++ b/fusion_static_dispatch.hpp
@@ -0,0 +1,127 @@
+#pragma once
+
+#include "index_list.hpp"
+#include "friendly_fusion.hpp"
+
+#include <boost/any.hpp>
+
+template <typename T, int index>
+struct TypeAt {
+	typedef friendly_fusion::result_of::begin<T> begin;
+	typedef friendly_fusion::result_of::advance_c<typename begin::type, index> adv_it;
+	typedef friendly_fusion::result_of::deref<typename adv_it::type> deref;
+	typedef typename std::decay<typename deref::type>::type value_type;
+};
+
+#if defined( __GNUC__ ) && !defined( __clang__ )
+template<int index, typename T>
+std::function<boost::any(T)> make_at_c_lambda(T seq)
+{
+	return [](T seq){
+		return boost::any(friendly_fusion::deref(friendly_fusion::advance_c<index>(friendly_fusion::begin(seq))));
+	};
+}
+#endif //defined( __GNUC__ ) && !defined( __clang__ )
+
+template<typename T, int... Indices>
+boost::any get_nth_impl(T seq, int index, indices<Indices...>)
+{
+	typedef std::function<boost::any(T)> element_type;
+	static element_type table[] =
+	{
+#if defined( __GNUC__ ) && !defined( __clang__ )
+		//Workaround for gcc bug: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47226
+		make_at_c_lambda<Indices>(seq)
+		...
+#else
+		[](T seq){return boost::any(friendly_fusion::deref(friendly_fusion::advance_c<Indices>(friendly_fusion::begin(seq))));}
+		...
+#endif //defined( __GNUC__ ) && !defined( __clang__ )
+	};
+
+	return table[index](seq);
+}
+
+template<typename T>
+struct get_nth_functor
+{
+	boost::any operator()(T seq, int index)
+	{
+		typedef typename friendly_fusion::result_of::size<T>::type seq_size;
+		typedef typename build_indices<seq_size::value>::type indices_type;
+	
+		return get_nth_impl(seq, index, indices_type{});
+	}
+};
+
+template <typename T>
+boost::any get_nth(T x, int index)
+{
+	return get_nth_functor<T>()(x, index);
+}
+
+#if defined( __GNUC__ ) && !defined( __clang__ )
+template<int index, typename T>
+std::function<std::string()> make_struct_member_name_lambda()
+{
+	return []{
+		return std::string(friendly_fusion::extension::struct_member_name<T, index>::call());
+	};
+}
+#endif //defined( __GNUC__ ) && !defined( __clang__ )
+
+template<typename T>
+struct get_nth_name_impl {
+	
+	get_nth_name_impl() = default;
+	
+	template<int... Indices>
+	std::string operator()(int index, indices<Indices...>)
+	{
+		typedef std::function<std::string()> element_type;
+		static element_type table[] = {
+	#if defined( __GNUC__ ) && !defined( __clang__ )
+			//Workaround for gcc bug: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47226
+			make_struct_member_name_lambda<Indices, T>()
+			...
+	#else
+			[]{return std::string(friendly_fusion::extension::struct_member_name<T, Indices>::call());}
+			...
+	#endif //defined( __GNUC__ ) && !defined( __clang__ )
+		};
+	
+		return table[index]();
+	}
+};
+
+template <typename T>
+struct get_nth_name_functor 
+{
+	std::string operator()(int index)
+	{
+		typedef typename friendly_fusion::result_of::size<T>::type seq_size;
+		typedef typename build_indices<seq_size::value>::type indices_type;
+	
+		return get_nth_name_impl<T>()(index, indices_type{});
+	}
+};
+
+template <typename T, typename U>
+struct get_nth_name_functor<boost::fusion::joint_view<T,U>>
+{
+	std::string operator()(int index)
+	{
+		constexpr size_t size_of_T = friendly_fusion::result_of::size<T>::type::value;
+		if(index < size_of_T){
+			return get_nth_name_functor<T>()(index);
+		} else {
+			return get_nth_name_functor<U>()(index - size_of_T);
+		}
+	}
+};
+
+template <typename T>
+std::string get_nth_name(int index)
+{
+	return get_nth_name_functor<T>()(index);
+}