template <size_t N> struct SFINAE {};
template <class U>
- static Yes &hasGetNext(
- SFINAE<sizeof(static_cast<NodeT *>(make<U>().getNext(&make<NodeT>())))>
- * = 0);
- template <class U> static No &hasGetNext(...);
+ static Yes &test(U *I, decltype(I->getNext(&make<NodeT>())) * = 0);
+ template <class> static No &test(...);
- static const bool value = sizeof(hasGetNext<TraitsT>(nullptr)) == sizeof(Yes);
+public:
+ static const bool value = sizeof(test<TraitsT>(nullptr)) == sizeof(Yes);
+};
+
+template <class TraitsT, class NodeT> struct HasObsoleteCustomization {
+ static const bool value = HasGetNext<TraitsT, NodeT>::value;
};
} // end namespace ilist_detail
///
template <typename NodeTy, typename Traits = ilist_traits<NodeTy>>
class iplist : public Traits, ilist_node_access {
-#if !defined(_MSC_VER)
- // FIXME: This fails in MSVC, but it's worth keeping around to help
- // non-Windows users root out bugs in their ilist_traits.
- static_assert(!ilist_detail::HasGetNext<Traits, NodeTy>::value,
- "ilist next and prev links are not customizable!");
-#endif
+ // TODO: Drop this assertion and the transitive type traits anytime after
+ // v4.0 is branched (i.e,. keep them for one release to help out-of-tree code
+ // update).
+ static_assert(!ilist_detail::HasObsoleteCustomization<Traits, NodeTy>::value,
+ "ilist customization points have changed!");
mutable NodeTy *Head;
EXPECT_EQ(6, List.back().Value);
}
+struct Empty {};
+TEST(ilistTest, HasObsoleteCustomizationTrait) {
+ // Negative test for HasObsoleteCustomization.
+ static_assert(!ilist_detail::HasObsoleteCustomization<Empty, Node>::value,
+ "Empty has no customizations");
}
+
+struct GetNext {
+ Node *getNext(Node *);
+};
+TEST(ilistTest, HasGetNextTrait) {
+ static_assert(ilist_detail::HasGetNext<GetNext, Node>::value,
+ "GetNext has a getNext(Node*)");
+ static_assert(ilist_detail::HasObsoleteCustomization<GetNext, Node>::value,
+ "Empty should be obsolete because of getNext()");
+
+ // Negative test for HasGetNext.
+ static_assert(!ilist_detail::HasGetNext<Empty, Node>::value,
+ "Empty does not have a getNext(Node*)");
+}
+
+} // end namespace