Index: src/AST/Pass.proto.hpp
===================================================================
--- src/AST/Pass.proto.hpp	(revision e46ea00cef7e26153189f49972efcac508f71897)
+++ src/AST/Pass.proto.hpp	(revision 93f74c0f041d552f34efb8041fc88182fa70b0c6)
@@ -119,5 +119,5 @@
 	template<typename core_t, typename node_t>
 	struct is_valid_previsit {
-		using ret_t = decltype( ((core_t*)nullptr)->previsit( (const node_t *)nullptr ) );
+		using ret_t = decltype( std::declval<core_t*>()->previsit( std::declval<const node_t *>() ) );
 
 		static constexpr bool value = std::is_void< ret_t >::value ||