Add `mrb_get_arg1()` that retrieves single (and only) argument.

`mrb_get_arg1()` raises `ArgumentError` if the method does not receive one
argument.

And replaces all `mrb_get_args(mrb, "o", &arg)` by the new function.

1 files changed, 5 insertions, 11 deletions

diff --git a/mrbgems/mruby-struct/src/struct.c b/mrbgems/mruby-struct/src/struct.c
index f42a5f1ea..7fbf9225f 100644
--- a/mrbgems/mruby-struct/src/struct.c
+++ b/mrbgems/mruby-struct/src/struct.c
@@ -154,9 +154,8 @@ mrb_struct_set_m(mrb_state *mrb, mrb_value obj)
 {
   mrb_int i = mrb_fixnum(mrb_proc_cfunc_env_get(mrb, 0));
   mrb_value *ptr;
-  mrb_value val;
+  mrb_value val = mrb_get_arg1(mrb);
 
-  mrb_get_args(mrb, "o", &val);
   mrb_struct_modify(mrb, obj);
   ptr = RSTRUCT_PTR(obj);
   if (ptr == NULL || i >= RSTRUCT_LEN(obj)) {
@@ -356,9 +355,7 @@ mrb_struct_initialize(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_struct_init_copy(mrb_state *mrb, mrb_value copy)
 {
-  mrb_value s;
-
-  mrb_get_args(mrb, "o", &s);
+  mrb_value s = mrb_get_arg1(mrb);
 
   if (mrb_obj_equal(mrb, copy, s)) return copy;
   if (!mrb_obj_is_instance_of(mrb, s, mrb_obj_class(mrb, copy))) {
@@ -428,9 +425,8 @@ struct_aref_int(mrb_state *mrb, mrb_value s, mrb_int i)
 static mrb_value
 mrb_struct_aref(mrb_state *mrb, mrb_value s)
 {
-  mrb_value idx;
+  mrb_value idx = mrb_get_arg1(mrb);
 
-  mrb_get_args(mrb, "o", &idx);
   if (mrb_string_p(idx)) {
     mrb_value sym = mrb_check_intern_str(mrb, idx);
 
@@ -545,11 +541,10 @@ mrb_struct_aset(mrb_state *mrb, mrb_value s)
 static mrb_value
 mrb_struct_equal(mrb_state *mrb, mrb_value s)
 {
-  mrb_value s2;
+  mrb_value s2 = mrb_get_arg1(mrb);
   mrb_value *ptr, *ptr2;
   mrb_int i, len;
 
-  mrb_get_args(mrb, "o", &s2);
   if (mrb_obj_equal(mrb, s, s2)) {
     return mrb_true_value();
   }
@@ -582,11 +577,10 @@ mrb_struct_equal(mrb_state *mrb, mrb_value s)
 static mrb_value
 mrb_struct_eql(mrb_state *mrb, mrb_value s)
 {
-  mrb_value s2;
+  mrb_value s2 = mrb_get_arg1(mrb);
   mrb_value *ptr, *ptr2;
   mrb_int i, len;
 
-  mrb_get_args(mrb, "o", &s2);
   if (mrb_obj_equal(mrb, s, s2)) {
     return mrb_true_value();
   }