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, 6 insertions, 8 deletions

diff --git a/mrbgems/mruby-kernel-ext/src/kernel.c b/mrbgems/mruby-kernel-ext/src/kernel.c
index 427740c1c..1d183aecd 100644
--- a/mrbgems/mruby-kernel-ext/src/kernel.c
+++ b/mrbgems/mruby-kernel-ext/src/kernel.c
@@ -128,9 +128,8 @@ mrb_f_integer(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_f_float(mrb_state *mrb, mrb_value self)
 {
-  mrb_value arg;
+  mrb_value arg = mrb_get_arg1(mrb);
 
-  mrb_get_args(mrb, "o", &arg);
   return mrb_Float(mrb, arg);
 }
 #endif
@@ -149,9 +148,9 @@ mrb_f_float(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_f_string(mrb_state *mrb, mrb_value self)
 {
-  mrb_value arg, tmp;
+  mrb_value arg = mrb_get_arg1(mrb);
+  mrb_value tmp;
 
-  mrb_get_args(mrb, "o", &arg);
   tmp = mrb_convert_type(mrb, arg, MRB_TT_STRING, "String", "to_s");
   return tmp;
 }
@@ -168,9 +167,9 @@ mrb_f_string(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_f_array(mrb_state *mrb, mrb_value self)
 {
-  mrb_value arg, tmp;
+  mrb_value arg = mrb_get_arg1(mrb);
+  mrb_value tmp;
 
-  mrb_get_args(mrb, "o", &arg);
   tmp = mrb_check_convert_type(mrb, arg, MRB_TT_ARRAY, "Array", "to_a");
   if (mrb_nil_p(tmp)) {
     return mrb_ary_new_from_values(mrb, 1, &arg);
@@ -196,9 +195,8 @@ mrb_f_array(mrb_state *mrb, mrb_value self)
 static mrb_value
 mrb_f_hash(mrb_state *mrb, mrb_value self)
 {
-  mrb_value arg;
+  mrb_value arg = mrb_get_arg1(mrb);
 
-  mrb_get_args(mrb, "o", &arg);
   if (mrb_nil_p(arg) || (mrb_array_p(arg) && RARRAY_LEN(arg) == 0)) {
     return mrb_hash_new(mrb);
   }