From 9a72bd661dc898623b7c84f3252fa31caa6bf257 Mon Sep 17 00:00:00 2001
From: Ilya Averyanov <a1ien.n3t@gmail.com>
Date: Mon, 30 Aug 2021 17:30:10 +0300
Subject: [PATCH] ConfigDescriptor and InterfaceDescriptor extra return just
 slice

Close #90
---
 examples/list_devices.rs    | 8 ++++----
 src/config_descriptor.rs    | 9 +++------
 src/interface_descriptor.rs | 9 +++------
 3 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/examples/list_devices.rs b/examples/list_devices.rs
index d4c9a15..21744b5 100644
--- a/examples/list_devices.rs
+++ b/examples/list_devices.rs
@@ -149,8 +149,8 @@ fn print_config<T: UsbContext>(config_desc: &ConfigDescriptor, handle: &mut Opti
     println!("      Remote Wakeup    {:>5}", config_desc.remote_wakeup());
     println!("    bMaxPower           {:4}mW", config_desc.max_power());
 
-    if let Some(extra) = config_desc.extra() {
-        println!("    {:?}", extra);
+    if !config_desc.extra().is_empty() {
+        println!("    {:?}", config_desc.extra());
     } else {
         println!("    no extra data");
     }
@@ -194,8 +194,8 @@ fn print_interface<T: UsbContext>(
             .unwrap_or(String::new()))
     );
 
-    if let Some(extra) = interface_desc.extra() {
-        println!("    {:?}", extra);
+    if interface_desc.extra().is_empty() {
+        println!("    {:?}", interface_desc.extra());
     } else {
         println!("    no extra data");
     }
diff --git a/src/config_descriptor.rs b/src/config_descriptor.rs
index 11fd957..c3ca071 100644
--- a/src/config_descriptor.rs
+++ b/src/config_descriptor.rs
@@ -71,14 +71,11 @@ impl ConfigDescriptor {
     }
 
     /// Returns the unknown 'extra' bytes that libusb does not understand.
-    pub fn extra(&self) -> Option<&[u8]> {
+    pub fn extra(&self) -> &[u8] {
         unsafe {
             match (*self.descriptor).extra_length {
-                len if len > 0 => Some(slice::from_raw_parts(
-                    (*self.descriptor).extra,
-                    len as usize,
-                )),
-                _ => None,
+                len if len > 0 => slice::from_raw_parts((*self.descriptor).extra, len as usize),
+                _ => &[],
             }
         }
     }
diff --git a/src/interface_descriptor.rs b/src/interface_descriptor.rs
index 87d3e46..56b155b 100644
--- a/src/interface_descriptor.rs
+++ b/src/interface_descriptor.rs
@@ -104,14 +104,11 @@ impl<'a> InterfaceDescriptor<'a> {
     }
 
     /// Returns the unknown 'extra' bytes that libusb does not understand.
-    pub fn extra(&self) -> Option<&[u8]> {
+    pub fn extra(&self) -> &[u8] {
         unsafe {
             match (*self.descriptor).extra_length {
-                len if len > 0 => Some(slice::from_raw_parts(
-                    (*self.descriptor).extra,
-                    len as usize,
-                )),
-                _ => None,
+                len if len > 0 => slice::from_raw_parts((*self.descriptor).extra, len as usize),
+                _ => &[],
             }
         }
     }