===================================================================
@@ -5517,13 +5517,21 @@ unify_method_type_error (bool explain_p, tree arg)
}
static int
-unify_arity (bool explain_p, int have, int wanted)
+unify_arity (bool explain_p, int have, int wanted, bool least_p = false)
{
if (explain_p)
- inform_n (input_location, wanted,
- " candidate expects %d argument, %d provided",
- " candidate expects %d arguments, %d provided",
- wanted, have);
+ {
+ if (least_p)
+ inform_n (input_location, wanted,
+ " candidate expects at least %d argument, %d provided",
+ " candidate expects at least %d arguments, %d provided",
+ wanted, have);
+ else
+ inform_n (input_location, wanted,
+ " candidate expects %d argument, %d provided",
+ " candidate expects %d arguments, %d provided",
+ wanted, have);
+ }
return 1;
}
@@ -5534,9 +5542,10 @@ unify_too_many_arguments (bool explain_p, int have
}
static int
-unify_too_few_arguments (bool explain_p, int have, int wanted)
+unify_too_few_arguments (bool explain_p, int have, int wanted,
+ bool least_p = false)
{
- return unify_arity (explain_p, have, wanted);
+ return unify_arity (explain_p, have, wanted, least_p);
}
static int
@@ -16617,18 +16626,33 @@ type_unification_real (tree tparms,
are present, and the parm list isn't variadic. */
if (ia < nargs && parms == void_list_node)
return unify_too_many_arguments (explain_p, nargs, ia);
- /* Fail if parms are left and they don't have default values. */
+ /* Fail if parms are left and they don't have default values and
+ they aren't all deduced as empty packs, eg (c++/57397):
+
+ template<class T1, class... Tn, class... Tm>
+ void foo(T1, Tn..., Tm...);
+
+ int main()
+ {
+ foo(1);
+ } */
if (parms && parms != void_list_node
&& TREE_PURPOSE (parms) == NULL_TREE)
{
unsigned int count = nargs;
tree p = parms;
- while (p && p != void_list_node)
+ bool type_pack_p;
+ do
{
- count++;
+ type_pack_p = TREE_CODE (TREE_VALUE (p)) == TYPE_PACK_EXPANSION;
+ if (!type_pack_p)
+ count++;
p = TREE_CHAIN (p);
}
- return unify_too_few_arguments (explain_p, ia, count);
+ while (p && p != void_list_node);
+ if (count != nargs)
+ return unify_too_few_arguments (explain_p, ia, count,
+ type_pack_p);
}
if (!subr)
===================================================================
@@ -0,0 +1,22 @@
+// PR c++/57397
+// { dg-do compile { target c++11 } }
+
+template<class T1, class... Tn>
+void foo(T1, Tn...);
+
+template<class T1, class T2, class... Tn>
+void bar(T1, T2, Tn...);
+
+int main()
+{
+ foo(); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 1 argument, 0 provided" "" { target *-*-* } 12 }
+ foo(1);
+ foo(1, 2);
+ bar(); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 2 arguments, 0 provided" "" { target *-*-* } 16 }
+ bar(1); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 2 arguments, 1 provided" "" { target *-*-* } 18 }
+ bar(1, 2);
+ bar(1, 2, 3);
+}
===================================================================
@@ -0,0 +1,24 @@
+// PR c++/57397
+// { dg-do compile { target c++11 } }
+
+template<class T1, class... Tn, class... Tm>
+void foo(T1, Tn..., Tm...);
+
+template<class T1, class T2, class... Tn, class... Tm>
+void bar(T1, T2, Tn..., Tm...);
+
+int main()
+{
+ foo(); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 1 argument, 0 provided" "" { target *-*-* } 12 }
+ foo(1);
+ foo(1, 2);
+ foo(1, 2, 3);
+ bar(); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 2 arguments, 0 provided" "" { target *-*-* } 17 }
+ bar(1); // { dg-error "no matching" }
+ // { dg-message "candidate expects at least 2 arguments, 1 provided" "" { target *-*-* } 19 }
+ bar(1, 2);
+ bar(1, 2, 3);
+ bar(1, 2, 3, 4);
+}