Define wrapper type for shared_ptr

rt/include/python/builtins.hpp

@@ -23,6 +23,26 @@
 
 using namespace std::literals;
 
+template<typename T>
+concept PyUserType = requires { typename T::type; };
+
+template<typename T>
+struct RealType {
+  using type = T;
+};
+
+template<PyUserType T>
+struct RealType<T> {
+  using type = typename T::type;
+};
+
+template <typename T> using PyObj = std::shared_ptr<typename RealType<T>::type>;
+
+template <typename T, typename... Args>
+auto pyobj(Args &&... args) -> PyObj<T> {
+  return std::make_shared<typename RealType<T>::type>(std::forward<Args>(args)...);
+}
+
 // typon_len
 
 template <typename T>

trans/transpiler/phases/emit_cpp/__init__.py

@@ -59,7 +59,7 @@ class NodeVisitor(UniversalVisitor):
         elif node is TY_STR:
             yield "std::string"
         elif isinstance(node, UserType):
-            yield f"std::shared_ptr<decltype({node.name})::type>"
+            yield f"PyObj<decltype({node.name})>"
         elif isinstance(node, TypeType):
             yield "auto"  # TODO
         elif isinstance(node, Promise):

trans/transpiler/phases/emit_cpp/class_.py

@@ -24,7 +24,7 @@ class ClassVisitor(NodeVisitor):
         yield "};"
 
         yield "template<typename... T> auto operator()(T&&... args) {"
-        yield "return std::make_shared<type>(std::forward<T>(args)...);"
+        yield "return pyobj<type>(std::forward<T>(args)...);"
         yield "}"
 
         outer = ClassOuterVisitor(node.inner_scope)