Use thiserror more widely for deriving Error/Display impls of error types

gstreamer-pbutils/Cargo.toml

@@ -21,6 +21,7 @@ gstreamer-sys = { git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs-s
 gstreamer-pbutils-sys = { git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs-sys", features = ["v1_8"] }
 glib = { git = "https://github.com/gtk-rs/glib" }
 gstreamer = { path = "../gstreamer" }
+thiserror = "1.0"
 
 [build-dependencies]
 rustdoc-stripper = { version = "0.1", optional = true }

gstreamer-pbutils/src/encoding_profile.rs

@@ -12,8 +12,7 @@ use gst;
 use gst_pbutils_sys;
 use gst_sys;
 
-use std::error;
-use std::fmt;
+use thiserror::Error;
 
 use glib::object::IsA;
 use glib::translate::*;
@@ -257,16 +256,9 @@ impl EncodingContainerProfile {
     }
 }
 
-#[derive(Debug, Clone)]
-pub struct EncodingProfileBuilderError;
-
-impl fmt::Display for EncodingProfileBuilderError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "failed to build encoding profile")
-    }
-}
-
-impl error::Error for EncodingProfileBuilderError {}
+#[derive(Debug, Clone, Error)]
+#[error("failed to build encoding profile")]
+pub struct EncodingProfileBuilderError(());
 
 #[derive(Debug)]
 struct EncodingProfileBuilderCommonData<'a> {
@@ -395,7 +387,7 @@ impl<'a> EncodingAudioProfileBuilder<'a> {
 
     pub fn build(self) -> Result<EncodingAudioProfile, EncodingProfileBuilderError> {
         if self.base.format.is_none() {
-            return Err(EncodingProfileBuilderError);
+            return Err(EncodingProfileBuilderError(()));
         }
 
         let profile = EncodingAudioProfile::new(
@@ -447,7 +439,7 @@ impl<'a> EncodingVideoProfileBuilder<'a> {
 
     pub fn build(self) -> Result<EncodingVideoProfile, EncodingProfileBuilderError> {
         if self.base.format.is_none() {
-            return Err(EncodingProfileBuilderError);
+            return Err(EncodingProfileBuilderError(()));
         }
 
         let video_profile = EncodingVideoProfile::new(
@@ -483,7 +475,7 @@ impl<'a> EncodingContainerProfileBuilder<'a> {
 
     pub fn build(self) -> Result<EncodingContainerProfile, EncodingProfileBuilderError> {
         if self.base.format.is_none() {
-            return Err(EncodingProfileBuilderError);
+            return Err(EncodingProfileBuilderError(()));
         }
 
         let container_profile = EncodingContainerProfile::new(
@@ -496,7 +488,7 @@ impl<'a> EncodingContainerProfileBuilder<'a> {
         for profile in self.profiles {
             container_profile
                 .add_profile(&profile)
-                .or_else(|_error| Err(EncodingProfileBuilderError))?;
+                .or_else(|_error| Err(EncodingProfileBuilderError(())))?;
         }
 
         set_common_fields(&container_profile, &self.base);

gstreamer-pbutils/src/lib.rs

@@ -20,6 +20,8 @@ extern crate gstreamer as gst;
 extern crate gstreamer_pbutils_sys as gst_pbutils_sys;
 extern crate gstreamer_sys as gst_sys;
 
+extern crate thiserror;
+
 static PBUTILS_INIT: Once = Once::new();
 
 macro_rules! assert_initialized_main_thread {

gstreamer/src/format.rs

@@ -9,6 +9,7 @@
 use muldiv::MulDiv;
 use std::convert::TryFrom;
 use std::ops;
+use thiserror::Error;
 use ClockTime;
 use Format;
 
@@ -36,17 +37,10 @@ pub struct Buffers(pub Option<u64>);
 #[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy, Debug, Default)]
 pub struct Percent(pub Option<u32>);
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
+#[error("invalid generic value format")]
 pub struct TryFromGenericFormattedValueError(());
 
-impl std::error::Error for TryFromGenericFormattedValueError {}
-
-impl std::fmt::Display for TryFromGenericFormattedValueError {
-    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(fmt, "invalid generic value format")
-    }
-}
-
 pub trait FormattedValue: Copy + Clone + Sized + Into<GenericFormattedValue> + 'static {
     fn get_default_format() -> Format;
     fn get_format(&self) -> Format;
@@ -670,17 +664,10 @@ impl AsMut<Option<u32>> for Percent {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Error)]
+#[error("value out of range")]
 pub struct TryPercentFromFloatError(());
 
-impl std::error::Error for TryPercentFromFloatError {}
-
-impl std::fmt::Display for TryPercentFromFloatError {
-    fn fmt(&self, fmt: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(fmt, "value out of range")
-    }
-}
-
 impl TryFrom<f64> for Percent {
     type Error = TryPercentFromFloatError;
 

gstreamer/src/structure.rs

@@ -7,7 +7,6 @@
 // except according to those terms.
 
 use std::borrow::{Borrow, BorrowMut, ToOwned};
-use std::error;
 use std::ffi::CStr;
 use std::fmt;
 use std::marker::PhantomData;
@@ -16,6 +15,8 @@ use std::ops::{Deref, DerefMut};
 use std::ptr;
 use std::str;
 
+use thiserror::Error;
+
 use Fraction;
 
 use glib;
@@ -28,13 +29,14 @@ use glib_sys::gpointer;
 use gobject_sys;
 use gst_sys;
 
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, Error)]
 pub enum GetError<'name> {
-    FieldNotFound {
-        name: &'name str,
-    },
+    #[error("GetError: Structure field with name {name} not found")]
+    FieldNotFound { name: &'name str },
+    #[error("GetError: Structure field with name {name} not retrieved")]
     ValueGetError {
         name: &'name str,
+        #[source]
         value_get_error: glib::value::GetError,
     },
 }
@@ -54,26 +56,6 @@ impl<'name> GetError<'name> {
     }
 }
 
-impl<'name> fmt::Display for GetError<'name> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            GetError::FieldNotFound { name } => {
-                write!(f, "GetError: Structure field with name {} not found", name)
-            }
-            GetError::ValueGetError {
-                name,
-                value_get_error,
-            } => write!(
-                f,
-                "GetError: Structure field with name {} value: {}",
-                name, value_get_error,
-            ),
-        }
-    }
-}
-
-impl<'name> error::Error for GetError<'name> {}
-
 pub struct Structure(ptr::NonNull<StructureRef>, PhantomData<StructureRef>);
 unsafe impl Send for Structure {}
 unsafe impl Sync for Structure {}