Fix missing error impls and format

Author: Andres de Lago Gomez

examples/sine_advanced.rs

@@ -5,8 +5,8 @@ extern crate coreaudio;
 
 use coreaudio::audio_unit::audio_format::LinearPcmFlags;
 use coreaudio::audio_unit::macos_helpers::{
-    audio_unit_from_device_id, find_matching_physical_format, get_default_device_id, get_hogging_pid,
-    get_supported_physical_stream_formats, set_device_physical_stream_format,
+    audio_unit_from_device_id, find_matching_physical_format, get_default_device_id,
+    get_hogging_pid, get_supported_physical_stream_formats, set_device_physical_stream_format,
     set_device_sample_rate, toggle_hog_mode, AliveListener, RateListener,
 };
 use coreaudio::audio_unit::render_callback::{self, data};

src/error.rs

@@ -41,6 +41,8 @@ pub mod audio {
         }
     }
 
+    impl std::error::Error for Error {}
+
     impl ::std::fmt::Display for Error {
         fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
             let description = match *self {
@@ -93,6 +95,8 @@ pub mod audio_codec {
         }
     }
 
+    impl std::error::Error for Error {}
+
     impl ::std::fmt::Display for Error {
         fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
             let description = match *self {
@@ -139,6 +143,8 @@ pub mod audio_format {
         }
     }
 
+    impl std::error::Error for Error {}
+
     impl ::std::fmt::Display for Error {
         fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
             let description = match *self {
@@ -209,6 +215,8 @@ pub mod audio_unit {
         }
     }
 
+    impl std::error::Error for Error {}
+
     impl ::std::fmt::Display for Error {
         fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
             let description = match *self {
@@ -302,6 +310,8 @@ impl Error {
     }
 }
 
+impl std::error::Error for Error {}
+
 impl ::std::fmt::Display for Error {
     fn fmt(&self, f: &mut ::std::fmt::Formatter) -> Result<(), ::std::fmt::Error> {
         match *self {