Teach the evaluation of the __is_convertible_to trait to translate

access control errors into SFINAE errors, so that the trait provides
enough support to implement the C++0x std::is_convertible type trait.

To get there, the SFINAETrap now knows how to set up a SFINAE context
independent of any template instantiations or template argument
deduction steps, and (separately) can set a Sema flag to translate
access control errors into SFINAE errors. The latter can also be
useful if we decide that access control errors during template argument
deduction should cause substitution failure (rather than a hard error)
as has been proposed for C++0x.

llvm-svn: 124446

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/type-traits.cpp b/clang/test/SemaCXX/type-traits.cpp
index 54d1236dd85..0ecec449637 100644
--- a/clang/test/SemaCXX/type-traits.cpp
+++ b/clang/test/SemaCXX/type-traits.cpp
@@ -502,6 +502,12 @@ struct FromInt { FromInt(int); };
 struct ToInt { operator int(); };
 typedef void Function();
 
+void is_convertible_to();
+class PrivateCopy {
+  PrivateCopy(const PrivateCopy&);
+  friend void is_convertible_to();
+};
+
 void is_convertible_to() {
   int t01[T(__is_convertible_to(Int, Int))];
   int t02[F(__is_convertible_to(Int, IntAr))];
@@ -524,4 +530,5 @@ void is_convertible_to() {
   int t19[T(__is_convertible_to(IntAr&, const IntAr&))];
   int t20[F(__is_convertible_to(const IntAr&, IntAr&))];
   int t21[F(__is_convertible_to(Function, Function))];
+  int t22[F(__is_convertible_to(PrivateCopy, PrivateCopy))];
 }