Revert "[Support][ErrorOr] Add support for convertable types."

This reverts commit a33e1fafac7fedb1b080ef07ddf9ad6ddff3a830.

This unit test crashes on Darwon. It needs to be temporarily reverted
to unblock the test infrastructure.

llvm-svn: 174458

include/llvm/Support/ErrorOr.h

@@ -162,7 +162,6 @@ public:
 /// T cannot be a rvalue reference.
 template<class T>
 class ErrorOr {
-  template <class OtherT> friend class ErrorOr;
   static const bool isRef = is_reference<T>::value;
   typedef ReferenceStorage<typename remove_reference<T>::type> wrap;
 
@@ -199,8 +198,7 @@ public:
     new (get()) storage_type(moveIfMoveConstructible<storage_type>(Val));
   }
 
-  template <class OtherT>
-  ErrorOr(ErrorOr<OtherT> &Other) : IsValid(false) {
+  ErrorOr(const ErrorOr &Other) : IsValid(false) {
     // Construct an invalid ErrorOr if other is invalid.
     if (!Other.IsValid)
       return;
@@ -228,8 +226,7 @@ public:
   }
 
 #if LLVM_HAS_RVALUE_REFERENCES
-  template <class OtherT>
-  ErrorOr(ErrorOr<OtherT> &&Other) : IsValid(false) {
+  ErrorOr(ErrorOr &&Other) : IsValid(false) {
     // Construct an invalid ErrorOr if other is invalid.
     if (!Other.IsValid)
       return;
@@ -311,6 +308,7 @@ private:
     return &Val->get();
   }
 
+protected:
   storage_type *get() {
     assert(IsValid && "Can't do anything on a default constructed ErrorOr!");
     assert(!HasError && "Cannot get value when an error exists!");

unittests/Support/ErrorOrTest.cpp

@@ -53,17 +53,6 @@ TEST(ErrorOr, Types) {
   EXPECT_EQ(3, **t3());
 #endif
 }
-
-struct B {};
-struct D : B {};
-
-TEST(ErrorOr, Covariant) {
-  ErrorOr<B*> b(ErrorOr<D*>(0));
-
-#if LLVM_HAS_CXX11_STDLIB
-  ErrorOr<std::unique_ptr<B> > b1(ErrorOr<std::unique_ptr<D> >(0));
-#endif
-}
 } // end anon namespace
 
 struct InvalidArgError {