re PR c++/58119 (Invalid ambiguous default type conversion with only a single…

re PR c++/58119 (Invalid ambiguous default type conversion with only a single invalid conversion listed.)

	PR c++/58119
	* cvt.c (build_expr_type_conversion): Don't complain about a
	template that can't match the desired type category.

From-SVN: r201880

gcc/cp/ChangeLog

+2013-08-20  Jason Merrill  <jason@redhat.com>
+
+	PR c++/58119
+	* cvt.c (build_expr_type_conversion): Don't complain about a
+	template that can't match the desired type category.
+
 2013-08-20  Gabriel Dos Reis  <gdr@integrable-solutions.net>
 
 	* error.c (pp_ggc_formatted_text): New.

gcc/cp/cvt.c

@@ -1590,17 +1590,6 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
       if (DECL_NONCONVERTING_P (cand))
 	continue;
 
-      if (TREE_CODE (cand) == TEMPLATE_DECL)
-	{
-	  if (complain)
-	    {
-	      error ("ambiguous default type conversion from %qT",
-		     basetype);
-	      error ("  candidate conversions include %qD", cand);
-	    }
-	  return error_mark_node;
-	}
-
       candidate = non_reference (TREE_TYPE (TREE_TYPE (cand)));
 
       switch (TREE_CODE (candidate))
@@ -1634,11 +1623,23 @@ build_expr_type_conversion (int desires, tree expr, bool complain)
 	  break;
 
 	default:
+	  /* A wildcard could be instantiated to match any desired
+	     type, but we can't deduce the template argument.  */
+	  if (WILDCARD_TYPE_P (candidate))
+	    win = true;
 	  break;
 	}
 
       if (win)
 	{
+	  if (TREE_CODE (cand) == TEMPLATE_DECL)
+	    {
+	      if (complain)
+		error ("default type conversion can't deduce template"
+		       " argument for %qD", cand);
+	      return error_mark_node;
+	    }
+
 	  if (winner)
 	    {
 	      tree winner_type

gcc/testsuite/g++.dg/template/delete2.C

+// PR c++/58119
+
+template <class T>
+struct A
+{
+  operator T*();
+  template <class U>
+  operator A<U>();
+};
+
+template <class T>
+struct B
+{
+  operator T*();
+  template <class U>
+  operator A<U>*();
+};
+
+int main()
+{
+  A<int> a;
+  delete a;
+
+  B<int> b;
+  delete b;			// { dg-error "template|delete" }
+}