Merge pull request #720 from skandhas/pr-add-mrb_check_hash_type

add mrb_check_hash_type

include/mruby/hash.h

@@ -29,6 +29,7 @@ mrb_value mrb_hash_fetch(mrb_state *mrb, mrb_value hash, mrb_value key, mrb_valu
 mrb_value mrb_hash_delete_key(mrb_state *mrb, mrb_value hash, mrb_value key);
 mrb_value mrb_hash(mrb_state *mrb, mrb_value obj);
 mrb_value mrb_hash_keys(mrb_state *mrb, mrb_value hash);
+mrb_value mrb_check_hash_type(mrb_state *mrb, mrb_value hash);
 
 /* RHASH_TBL allocates st_table if not available. */
 #define RHASH(obj)   ((struct RHash*)((obj).value.p))

src/hash.c

@@ -187,6 +187,12 @@ mrb_hash_modify_check(mrb_state *mrb, mrb_value hash)
   //if (OBJ_FROZEN(hash)) mrb_error_frozen("hash");
 }
 
+mrb_value
+mrb_check_hash_type(mrb_state *mrb, mrb_value hash)
+{
+  return mrb_check_convert_type(mrb, hash, MRB_TT_HASH, "Hash", "to_hash");
+}
+
 khash_t(ht) *
 mrb_hash_tbl(mrb_state *mrb, mrb_value hash)
 {