Fix compilation error on older compilers

Author: pum1k

include/class_loader/interface_traits.hpp

@@ -162,6 +162,14 @@ template<class Base, class ... Args>
 constexpr bool is_interface_constructible_v =
   is_interface_constructible<Base, Args...>::value;
 
+namespace impl
+{
+
+template<class ...>
+constexpr bool false_v = false;
+
+}  // namespace impl
+
 }  // namespace class_loader
 
 #endif  // CLASS_LOADER__INTERFACE_TRAITS_HPP_

include/class_loader/meta_object.hpp

@@ -154,9 +154,9 @@ class CLASS_LOADER_PUBLIC AbstractMetaObjectBase
   AbstractMetaObjectBaseImpl * impl_;
 };
 
-template<class ...>
+template<class ... Ts>
 class AbstractMetaObjectImpl {
-  static_assert(false, "Base template selected.");
+  static_assert(false_v<Ts...>, "Base template selected.");
 };
 
 template<class B, class ... Args>
@@ -204,9 +204,9 @@ class AbstractMetaObject : public AbstractMetaObjectImpl<interface_constructor_s
   AbstractMetaObject & operator=(const AbstractMetaObject &);
 };
 
-template<class ...>
+template<class ... Ts>
 class MetaObjectImpl {
-  static_assert(false, "Base template selected.");
+  static_assert(false_v<Ts...>, "Base template selected.");
 };
 
 template<class C, class B, class ... Args>