Prefer rb_check_arity when 0 or 1 arguments

Especially over checking argc then calling rb_scan_args just to
raise an ArgumentError.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 2 insertions, 5 deletions

diff --git a/enumerator.c b/enumerator.c
index e84785a6b8..615f933778 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -604,12 +604,9 @@ enumerator_with_index(int argc, VALUE *argv, VALUE obj)
 {
     VALUE memo;
 
-    rb_scan_args(argc, argv, "01", &memo);
+    rb_check_arity(argc, 0, 1);
     RETURN_SIZED_ENUMERATOR(obj, argc, argv, enumerator_enum_size);
-    if (NIL_P(memo))
-	memo = INT2FIX(0);
-    else
-	memo = rb_to_int(memo);
+    memo = (!argc || NIL_P(memo = argv[0])) ? INT2FIX(0) : rb_to_int(memo);
     return enumerator_block_call(obj, enumerator_with_index_i, (VALUE)MEMO_NEW(memo, 0, 0));
 }