use mrb_str_cat_str() instead of mrb_str_append()

If the argument is always a string, then mrb_str_cat_str() can be
directly called instead of indirectly by mrb_str_append().

mrb_any_to_s(), mrb_obj_as_string(), mrb_inspect() always return a
string.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/class.c b/src/class.c
index 1d54c91f4..33fb61211 100644
--- a/src/class.c
+++ b/src/class.c
@@ -1608,10 +1608,10 @@ mrb_mod_to_s(mrb_state *mrb, mrb_value klass)
       case MRB_TT_CLASS:
       case MRB_TT_MODULE:
       case MRB_TT_SCLASS:
-        mrb_str_append(mrb, str, mrb_inspect(mrb, v));
+        mrb_str_cat_str(mrb, str, mrb_inspect(mrb, v));
         break;
       default:
-        mrb_str_append(mrb, str, mrb_any_to_s(mrb, v));
+        mrb_str_cat_str(mrb, str, mrb_any_to_s(mrb, v));
         break;
     }
     return mrb_str_cat_lit(mrb, str, ">");