1 files changed, 21 insertions, 0 deletions
diff --git a/enum.c b/enum.c
index 419a2b98e4..919c53b482 100644
--- a/enum.c
+++ b/enum.c
@@ -1187,6 +1187,27 @@ enum_zip(int argc, VALUE *argv, VALUE obj)
     return result;
 }
 
+static VALUE
+in_i(VALUE i, VALUE *memo)
+{
+    if (rb_equal(i, memo[0])) {
+	memo[1] = Qtrue;
+	rb_iter_break();
+    }
+    return Qnil;
+}
+
+VALUE
+rb_enum_in(VALUE elem, VALUE obj)
+{
+    VALUE memo[2];
+
+    memo[0] = elem;
+    memo[1] = Qfalse;
+    rb_block_call(obj, id_each, 0, 0, in_i, (VALUE)&memo);
+    return memo[1];
+}
+
 /*
  *  The <code>Enumerable</code> mixin provides collection classes with
  *  several traversal and searching methods, and with the ability to