Let Fixnum#{ceil,floor,round,truncate} to return itself; #3652

src/numeric.c

@@ -1334,6 +1334,10 @@ mrb_init_numeric(mrb_state *mrb)
   mrb_define_method(mrb, fixnum,  "to_s",     fix_to_s,          MRB_ARGS_NONE()); /* 15.2.8.3.25 */
   mrb_define_method(mrb, fixnum,  "inspect",  fix_to_s,          MRB_ARGS_NONE());
   mrb_define_method(mrb, fixnum,  "divmod",   fix_divmod,        MRB_ARGS_REQ(1)); /* 15.2.8.3.30 (x) */
+  mrb_define_method(mrb, fixnum,  "ceil",     int_to_i,          MRB_ARGS_REQ(1)); /* 15.2.8.3.8 (x) */
+  mrb_define_method(mrb, fixnum,  "floor",    int_to_i,          MRB_ARGS_REQ(1)); /* 15.2.8.3.10 (x) */
+  mrb_define_method(mrb, fixnum,  "round",    int_to_i,          MRB_ARGS_REQ(1)); /* 15.2.8.3.12 (x) */
+  mrb_define_method(mrb, fixnum,  "truncate", int_to_i,          MRB_ARGS_REQ(1)); /* 15.2.8.3.15 (x) */
 
   /* Float Class */
   mrb->float_class = fl = mrb_define_class(mrb, "Float", numeric);                 /* 15.2.9 */