always check lang id list length

Author: eZioPan

src/device_builder.rs

@@ -164,14 +164,17 @@ impl<'a, B: UsbBus> UsbDeviceBuilder<'a, B> {
             "Not support more than 16 \"manufacturer\"s"
         );
 
-        // do list length check only if user already specify "extra_lang_ids"
-        let num_extra_langs = self.config.extra_lang_ids.as_ref().map(|langs| langs.len()).unwrap_or(0);
-        
+        let num_extra_langs = self
+            .config
+            .extra_lang_ids
+            .as_ref()
+            .map(|langs| langs.len())
+            .unwrap_or(0);
+
         assert!(
             manufacturer_ls.len() == num_extra_langs + 1,
             "The length of \"manufacturer\" list should be one more than \"extra_lang_ids\" list",
-        )
-
+        );
 
         self.config.manufacturer = Some(manufacturer_ls);
 
@@ -195,13 +198,17 @@ impl<'a, B: UsbBus> UsbDeviceBuilder<'a, B> {
             "Not support more than 16 \"product\"s"
         );
 
-        // do list length check only if user already specify "extra_lang_ids"
-        if let Some(extra_lang_ids) = self.config.extra_lang_ids {
-            assert!(
-                product_ls.len() == extra_lang_ids.len() + 1,
-                "The length of \"product\" list should be one more than \"extra_lang_ids\" list",
-            )
-        }
+        let num_extra_langs = self
+            .config
+            .extra_lang_ids
+            .as_ref()
+            .map(|langs| langs.len())
+            .unwrap_or(0);
+
+        assert!(
+            product_ls.len() == num_extra_langs + 1,
+            "The length of \"product\" list should be one more than \"extra_lang_ids\" list",
+        );
 
         self.config.product = Some(product_ls);
 
@@ -225,13 +232,17 @@ impl<'a, B: UsbBus> UsbDeviceBuilder<'a, B> {
             "Not support more than 16 \"serial_number\"s"
         );
 
-        // do list length check only if user already specify "extra_lang_ids"
-        if let Some(extra_lang_ids) = self.config.extra_lang_ids {
-            assert!(
-                serial_number_ls.len() == extra_lang_ids.len() + 1,
-                "The length of \"serial_number\" list should be one more than \"extra_lang_ids\" list",
-            )
-        }
+        let num_extra_langs = self
+            .config
+            .extra_lang_ids
+            .as_ref()
+            .map(|langs| langs.len())
+            .unwrap_or(0);
+
+        assert!(
+            serial_number_ls.len() == num_extra_langs + 1,
+            "The length of \"serial_number\" list should be one more than \"extra_lang_ids\" list",
+        );
 
         self.config.serial_number = Some(serial_number_ls);