Define the new operator<< for sets into namespace std, so that

argument-dependent lookup can find it. This is another case where an
LLVM bug (not making operator<< visible) was masked by a GCC bug
(looking in the global namespace when it shouldn't).

llvm-svn: 92144

unittests/ADT/DeltaAlgorithmTest.cpp

@@ -13,6 +13,8 @@
 #include <cstdarg>
 using namespace llvm;
 
+namespace std {
+
 std::ostream &operator<<(std::ostream &OS,
                          const std::set<unsigned> &S) {
   OS << "{";
@@ -26,6 +28,8 @@ std::ostream &operator<<(std::ostream &OS,
   return OS;
 }
 
+}
+
 namespace {
 
 class FixedDeltaAlgorithm : public DeltaAlgorithm {