completed implicit type casters for reference_wrapper
diff --git a/example/issues.py b/example/issues.py
index 4095daa..e0726f0 100644
--- a/example/issues.py
+++ b/example/issues.py
@@ -5,7 +5,7 @@
from example.issues import print_cchar, print_char
from example.issues import DispatchIssue, dispatch_issue_go
-from example.issues import return_vec_of_reference_wrapper
+from example.issues import Placeholder ,return_vec_of_reference_wrapper
print_cchar("const char *")
print_char('c')
@@ -28,4 +28,4 @@
b = PyClass2()
dispatch_issue_go(b)
-print(return_vec_of_reference_wrapper())
+print(return_vec_of_reference_wrapper(Placeholder(4)))