Improve our handling of user-defined conversions when computing
implicit conversion sequences. In particular, model the "standard
conversion" from a class to its own type (or a base type) directly as
a standard conversion in the normal path *without* trying to determine
if there is a valid copy constructor. This appears to match the intent
of C++ [over.best.ics]p6 and more closely matches GCC and EDG.
As part of this, model non-lvalue reference initialization via
user-defined conversion in overloading the same way we handle it in
InitializationSequence, separating the "general user-defined
conversion" and "conversion to compatible class type" cases.
The churn in the overload-call-copycon.cpp test case is because the
test case was originally wrong; it assumed that we should do more
checking for copy constructors that we actually should, which affected
overload resolution.
Fixes PR7055. Bootstrapped okay.
llvm-svn: 110773
diff --git a/clang/test/SemaCXX/conversion-function.cpp b/clang/test/SemaCXX/conversion-function.cpp
index d7d41a4..73b78f4 100644
--- a/clang/test/SemaCXX/conversion-function.cpp
+++ b/clang/test/SemaCXX/conversion-function.cpp
@@ -214,3 +214,37 @@
void test_any() {
Any any = Other(); // expected-error{{cannot pass object of non-POD type 'Other' through variadic constructor; call will abort at runtime}}
}
+
+namespace PR7055 {
+ // Make sure that we don't allow too many conversions in an
+ // auto_ptr-like template. In particular, we can't create multiple
+ // temporary objects when binding to a reference.
+ struct auto_ptr {
+ struct auto_ptr_ref { };
+
+ auto_ptr(auto_ptr&);
+ auto_ptr(auto_ptr_ref);
+ explicit auto_ptr(int *);
+
+ operator auto_ptr_ref();
+ };
+
+ struct X {
+ X(auto_ptr);
+ };
+
+ X f() {
+ X x(auto_ptr(new int));
+ return X(auto_ptr(new int));
+ }
+
+ auto_ptr foo();
+
+ X e(foo());
+
+ struct Y {
+ Y(X);
+ };
+
+ Y f2(foo());
+}