Added functionality to allow returning wrapped classes from member functions

src/vu8/Class.hpp

@@ -9,12 +9,15 @@
 #include <vu8/detail/Proto.hpp>
 #include <vu8/detail/Singleton.hpp>
 #include <vu8/detail/Class.hpp>
+#include <vu8/detail/TypeTraits.hpp>
 
 #include <boost/fusion/container/vector.hpp>
 #include <boost/fusion/adapted/mpl.hpp>
 #include <boost/fusion/include/push_front.hpp>
 #include <boost/fusion/include/join.hpp>
 
+#include <boost/type_traits/is_void.hpp>
+
 #include <iostream>
 #include <stdexcept>
 
@@ -64,7 +67,7 @@ struct ClassSingletonFactory<M, NoFactory> {
 
 template <class T, class Factory>
 class ClassSingleton
-  : detail::LazySingleton< ClassSingleton<T, Factory> >,
+  : private detail::LazySingleton< ClassSingleton<T, Factory> >,
     public ClassSingletonFactory<ClassSingleton<T, Factory>, Factory>
 {
     friend class ClassSingletonFactory<ClassSingleton<T, Factory>, Factory>;
@@ -96,20 +99,38 @@ class ClassSingleton
     }
 
     template <class P>
-    static inline typename boost::disable_if<
-        boost::is_same<void, typename P::return_type>, ValueHandle >::type
-    ForwardReturn(T *obj, const v8::Arguments& args) {
+    static inline typename
+    boost::enable_if<vu8::is_to_v8_convertible<typename P::return_type>,
+    ValueHandle >::type ForwardReturn (T *obj, const v8::Arguments& args) {
         return ToV8(Invoke<P>(obj, args));
     }
 
     template <class P>
-    static inline typename boost::enable_if<
-        boost::is_same<void, typename P::return_type>, ValueHandle >::type
-    ForwardReturn(T *obj, const v8::Arguments& args) {
+    static inline typename
+    boost::enable_if<boost::is_void<typename P::return_type>,
+    ValueHandle >::type ForwardReturn (T *obj, const v8::Arguments& args) {
         Invoke<P>(obj, args);
         return v8::Undefined();
     }
 
+    template <class P>
+    static inline typename
+    boost::enable_if<typename P::IS_RETURN_WRAPPED_CLASS,
+    ValueHandle >::type ForwardReturn (T *obj, const v8::Arguments& args) {
+        typedef typename P::ClassSingleton LocalSelf;
+        typedef typename P::return_type ReturnType;
+
+        v8::HandleScope scope;
+        ReturnType* return_value = new ReturnType(Invoke<P>(obj, args));
+        v8::Local<v8::Object> localObj =
+            LocalSelf::Instance().func_->GetFunction()->NewInstance();
+        v8::Persistent<v8::Object> persistentObj =
+            v8::Persistent<v8::Object>::New(localObj);
+        persistentObj->SetInternalField(0, v8::External::New(return_value));
+        persistentObj.MakeWeak(return_value, &LocalSelf::MadeWeak);
+        return scope.Close(localObj);
+    }
+
     // every method is run inside a handle scope
     template <class P>
     static inline ValueHandle Forward(const v8::Arguments& args) {

src/vu8/detail/ProtoHelper.hpp

@@ -7,11 +7,17 @@
 #       include <boost/preprocessor/punctuation/comma_if.hpp>
 #       include <boost/preprocessor/iteration/iterate.hpp>
 #       include <boost/mpl/vector.hpp>
+#       include <boost/type_traits/integral_constant.hpp>
 
 #       ifndef VU8_PROTO_MAX_SIZE
 #         define VU8_PROTO_MAX_SIZE VU8_PP_ITERATION_LIMIT
 #       endif
-namespace vu8 { namespace detail {
+namespace vu8 {
+
+template <class T, class F> struct Class;
+template <class T, class F> struct ClassSingleton;
+
+namespace detail {
 
 namespace mpl = boost::mpl;
 
@@ -48,12 +54,30 @@ template <class C, class R BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM_PARAMS(n, class A)
 struct MemFunProto<C, R ( BOOST_PP_ENUM_PARAMS(n, A) )> : FunProtoBase<R> {
     typedef mpl::vector<BOOST_PP_ENUM_PARAMS(n, A)>   arguments;
     typedef R(C::*method_type)(BOOST_PP_ENUM_PARAMS(n, A));
+    typedef boost::false_type IS_RETURN_WRAPPED_CLASS;
+};
+
+template <class C, class R, class Factory BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM_PARAMS(n, class A)>
+struct MemFunProto<C, vu8::Class<R, Factory> ( BOOST_PP_ENUM_PARAMS(n, A) )> : FunProtoBase<R> {
+    typedef mpl::vector<BOOST_PP_ENUM_PARAMS(n, A)>   arguments;
+    typedef R(C::*method_type)(BOOST_PP_ENUM_PARAMS(n, A));
+    typedef boost::true_type IS_RETURN_WRAPPED_CLASS;
+    typedef vu8::ClassSingleton<R, Factory> ClassSingleton;
 };
 
 template <class C, class R BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM_PARAMS(n, class A)>
 struct MemFunProto<C const, R ( BOOST_PP_ENUM_PARAMS(n, A) )> : FunProtoBase<R> {
     typedef mpl::vector<BOOST_PP_ENUM_PARAMS(n, A)>   arguments;
     typedef R(C::*method_type)(BOOST_PP_ENUM_PARAMS(n, A)) const;
+    typedef boost::false_type IS_RETURN_WRAPPED_CLASS;
+};
+
+template <class C, class R, class Factory BOOST_PP_COMMA_IF(n) BOOST_PP_ENUM_PARAMS(n, class A)>
+struct MemFunProto<C const, vu8::Class<R, Factory> ( BOOST_PP_ENUM_PARAMS(n, A) )> : FunProtoBase<R> {
+    typedef mpl::vector<BOOST_PP_ENUM_PARAMS(n, A)>   arguments;
+    typedef R(C::*method_type)(BOOST_PP_ENUM_PARAMS(n, A)) const;
+    typedef boost::true_type IS_RETURN_WRAPPED_CLASS;
+    typedef vu8::ClassSingleton<R, Factory> ClassSingleton;
 };
 
 } }

src/vu8/detail/TypeTraits.hpp

@@ -0,0 +1,43 @@
+#ifndef TYPETRAITS_HPP_
+#define TYPETRAITS_HPP_
+
+#include <string>
+
+#include <boost/type_traits/integral_constant.hpp>
+#include <boost/type_traits/is_arithmetic.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/remove_const.hpp>
+#include <boost/type_traits/remove_reference.hpp>
+
+#include <boost/utility/enable_if.hpp>
+
+#include <v8.h>
+
+namespace vu8 {
+
+template <class T> struct remove_reference_and_const {
+    typedef typename boost::remove_const<
+        typename boost::remove_reference<T>::type
+    >::type type;
+};
+
+template <class T, class Enable = void>
+struct is_to_v8_convertible : public boost::false_type { };
+
+template <class T>
+struct is_to_v8_convertible<T, typename boost::enable_if<
+    boost::is_arithmetic<T>
+>::type> : public boost::true_type { };
+
+#define VU8_TO_V8_CONV_TYPE_TRAIT_SPEC(T,M,spec) \
+template <class T > \
+struct is_to_v8_convertible<T, typename boost::enable_if< \
+    boost::is_same<M, spec > \
+>::type> : public boost::true_type { }; \
+/**/
+
+VU8_TO_V8_CONV_TYPE_TRAIT_SPEC(T,T,v8::Handle<v8::Value>);
+VU8_TO_V8_CONV_TYPE_TRAIT_SPEC(T,typename remove_reference_and_const<T>::type, std::string);
+}
+
+#endif /* TYPETRAITS_HPP_ */