re PR c++/42761 (std::bind doesn't work for simple class types)

	PR c++/42761
	* semantics.c (finish_decltype_type): Within a template, treat
	unresolved CALL_EXPR as dependent.

From-SVN: r155966

gcc/cp/ChangeLog

+2010-01-16  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42761
+	* semantics.c (finish_decltype_type): Within a template, treat
+	unresolved CALL_EXPR as dependent.
+
 2010-01-15  Dodji Seketeli  <dodji@redhat.com>
 
 	* error.c (dump_template_parms,count_non_default_template_args):

gcc/cp/semantics.c

@@ -4803,6 +4803,7 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p)
       if (type && !type_uses_auto (type))
 	return type;
 
+    treat_as_dependent:
       type = cxx_make_type (DECLTYPE_TYPE);
       DECLTYPE_TYPE_EXPR (type) = expr;
       DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (type)
@@ -4930,6 +4931,11 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p)
                   && (TREE_CODE (TREE_TYPE (target_type)) == FUNCTION_TYPE
                       || TREE_CODE (TREE_TYPE (target_type)) == METHOD_TYPE))
                 type = TREE_TYPE (TREE_TYPE (target_type));
+	      else if (processing_template_decl)
+		/* Within a template finish_call_expr doesn't resolve
+		   CALL_EXPR_FN, so even though this decltype isn't really
+		   dependent let's defer resolving it.  */
+		goto treat_as_dependent;
               else
                 sorry ("unable to determine the declared type of expression %<%E%>",
                        expr);

gcc/testsuite/ChangeLog

+2010-01-15  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42761
+	* g++.dg/cpp0x/decltype22.C: New.
+
 2010-01-16  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/42760

gcc/testsuite/g++.dg/cpp0x/decltype22.C

+// PR c++/42761
+// { dg-options "-std=c++0x" }
+
+template<typename _Tp> _Tp* fn();
+
+template <class T> struct A
+{
+  template <class U,
+	    class S = decltype(fn<T>())>
+  struct B { };
+};
+
+A<int> a;