P0036R0: Unary Folds and Empty Parameter Packs

	* pt.c (expand_empty_fold): Remove special cases for *,+,&,|.

From-SVN: r234068

gcc/cp/ChangeLog

+2016-03-08  Jason Merrill  <jason@redhat.com>
+
+	P0036R0: Unary Folds and Empty Parameter Packs
+	* pt.c (expand_empty_fold): Remove special cases for *,+,&,|.
+
 2016-03-08  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/70135

gcc/cp/pt.c

@@ -10629,10 +10629,6 @@ gen_elem_of_pack_expansion_instantiation (tree pattern,
    sequence, the value of the expression is as follows; the program is
    ill-formed if the operator is not listed in this table.
 
-   *	1
-   +	0
-   &	-1
-   |	0
    &&	true
    ||	false
    ,	void()  */
@@ -10644,14 +10640,6 @@ expand_empty_fold (tree t, tsubst_flags_t complain)
   if (!FOLD_EXPR_MODIFY_P (t))
     switch (code)
       {
-      case MULT_EXPR:
-	return integer_one_node;
-      case PLUS_EXPR:
-	return integer_zero_node;
-      case BIT_AND_EXPR:
-	return integer_minus_one_node;
-      case BIT_IOR_EXPR:
-	return integer_zero_node;
       case TRUTH_ANDIF_EXPR:
 	return boolean_true_node;
       case TRUTH_ORIF_EXPR:

gcc/testsuite/g++.dg/cpp1z/fold1.C

@@ -22,11 +22,11 @@ MAKE_FNS (add, +);
 MAKE_FNS (sub, -);
 
 int main() {
-  assert(unary_left_add() == 0);
+  // assert(unary_left_add() == 0);
   assert(unary_left_add(1) == 1);
   assert(unary_left_add(1, 2, 3) == 6);
 
-  assert(unary_right_add() == 0);
+  // assert(unary_right_add() == 0);
   assert(unary_right_add(1) == 1);
   assert(unary_right_add(1, 2, 3) == 6);
 

gcc/testsuite/g++.dg/cpp1z/fold3.C

@@ -47,16 +47,16 @@ MAKE_FN (dot_star, .*);
 MAKE_FN (arrow_star, ->*);
 
 int main() {
-  static_assert(add() == int(), "");
-  static_assert(mul() == 1, "");
-  static_assert(bor() == int(), "");
-  static_assert(band() == -1, "");
   static_assert(land() == true, "");
   static_assert(lor() == false, "");
   comma(); // No value to theck
 
   // These are all errors, but the error is emitted at the point
   // of instantiation (line 10).
+  add();			// { dg-message "required from here" }
+  mul();			// { dg-message "required from here" }
+  bor();			// { dg-message "required from here" }
+  band();			// { dg-message "required from here" }
   sub();			// { dg-message "required from here" }
   div();			// { dg-message "required from here" }
   mod();			// { dg-message "required from here" }