out_c += "\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n"
out_c += f"\tassert(obj->tag == {struct_name}_{var.var_name});\n"
if field_map.ret_conv is not None:
out_c += "\t" + struct_name + " *obj = (" + struct_name + "*)untag_ptr(ptr);\n"
out_c += f"\tassert(obj->tag == {struct_name}_{var.var_name});\n"
if field_map.ret_conv is not None: