Part of PR15673: If a function template has a default argument in which
substitution failed, report that as a substitution failure rather than
pretending that there was no default argument.
The test cases in PR15673 have exposed some pre-existing poor diagnostics here.
llvm-svn: 185604
diff --git a/clang/test/SemaTemplate/overload-candidates.cpp b/clang/test/SemaTemplate/overload-candidates.cpp
index ad65397..544d897 100644
--- a/clang/test/SemaTemplate/overload-candidates.cpp
+++ b/clang/test/SemaTemplate/overload-candidates.cpp
@@ -79,3 +79,48 @@
void test() {
foo(NS1::array<int>()); // expected-error{{no matching function for call to 'foo'}}
}
+
+namespace std {
+ template<bool, typename = void> struct enable_if {};
+ template<typename T> struct enable_if<true, T> { typedef T type; };
+
+ template<typename T, T V> struct integral_constant { static const T value = V; };
+ typedef integral_constant<bool, false> false_type;
+ typedef integral_constant<bool, true> true_type;
+};
+
+namespace PR15673 {
+ template<typename T>
+ struct a_trait : std::false_type {};
+
+ template<typename T,
+ typename Requires = typename std::enable_if<a_trait<T>::value>::type> // expected-warning {{C++11 extension}}
+ // expected-note@-1 {{candidate template ignored: disabled by 'enable_if' [with T = int]}}
+ void foo() {}
+ void bar() { foo<int>(); } // expected-error {{no matching function for call to 'foo'}}
+
+
+ template<typename T>
+ struct some_trait : std::false_type {};
+
+ // FIXME: It would be nice to tunnel the 'disabled by enable_if' diagnostic through here.
+ template<typename T>
+ struct a_pony : std::enable_if<some_trait<T>::value> {};
+
+ template<typename T,
+ typename Requires = typename a_pony<T>::type> // expected-warning {{C++11 extension}}
+ // FIXME: The source location here is poor.
+ void baz() { } // expected-note {{candidate template ignored: substitution failure [with T = int]: no type named 'type' in 'PR15673::a_pony<int>'}}
+ void quux() { baz<int>(); } // expected-error {{no matching function for call to 'baz'}}
+
+
+ // FIXME: This note doesn't make it clear which candidate we rejected.
+ template <typename T>
+ using unicorns = typename std::enable_if<some_trait<T>::value>::type; // expected-warning {{C++11 extension}}
+ // expected-note@-1 {{candidate template ignored: disabled by 'enable_if' [with T = int]}}
+
+ template<typename T,
+ typename Requires = unicorns<T> > // expected-warning {{C++11 extension}}
+ void wibble() {}
+ void wobble() { wibble<int>(); } // expected-error {{no matching function for call to 'wibble'}}
+}