fix: clippy

Signed-off-by: Harald Hoyer <harald@hoyer.xyz>

examples/example.rs

@@ -18,7 +18,7 @@ fn func3() -> Result<(), Box<dyn Error + Send + Sync>> {
 derive_str_context!(Func2Error);
 
 fn func2() -> ChainResult<(), Func2Error> {
-    func3().context(Func2Error(format!("func2 error: calling func3")))?;
+    func3().context(Func2Error("func2 error: calling func3".to_string()))?;
     Ok(())
 }
 

examples/tutorial15.rs

@@ -84,7 +84,7 @@ pub mod mycrate {
 
         let filename = "bar.txt";
 
-        do_some_io(filename).map_context(|e| ErrorKind::from_io_error(&e, filename.into()))?;
+        do_some_io(filename).map_context(|e| ErrorKind::from_io_error(e, filename.into()))?;
         do_some_io(filename).map_context(|_| ErrorKind::IO(filename.into()))?;
         do_some_io(filename).map_context(|e| ErrorKind::from(e))?;
 

examples/tutorial7.rs

@@ -15,7 +15,7 @@ fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
 }
 
 fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
-    func2().context(format!("func1 error"))?;
+    func2().context("func1 error")?;
     Ok(())
 }
 

examples/tutorial8.rs

@@ -19,7 +19,7 @@ fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
 derive_str_context!(Func1Error);
 
 fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
-    func2().context(Func1Error(format!("func1 error")))?;
+    func2().context(Func1Error("func1 error".to_string()))?;
     Ok(())
 }
 

examples/tutorial9.rs

@@ -20,7 +20,7 @@ derive_str_context!(Func1ErrorFunc2);
 derive_str_context!(Func1ErrorIO);
 
 fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
-    func2().context(Func1ErrorFunc2(format!("func1 error calling func2")))?;
+    func2().context(Func1ErrorFunc2("func1 error calling func2".to_string()))?;
     let filename = "bar.txt";
     do_some_io().context(Func1ErrorIO(format!("Error reading '{}'", filename)))?;
     Ok(())

src/lib.rs

@@ -103,7 +103,6 @@
 //! Read the [Tutorial](https://haraldh.github.io/chainerror/tutorial1.html)
 
 #![deny(clippy::all)]
-#![deny(clippy::integer_arithmetic)]
 #![allow(clippy::needless_doctest_main)]
 #![deny(missing_docs)]
 
@@ -198,7 +197,9 @@ impl<T: 'static + Display + Debug> ChainError<T> {
     /// ```
     #[inline]
     pub fn find_cause<U: Error + 'static>(&self) -> Option<&U> {
-        self.iter().filter_map(Error::downcast_ref::<U>).next()
+        self.iter()
+            .filter_map(<dyn Error>::downcast_ref::<U>)
+            .next()
     }
 
     /// Find the first error cause of type `ChainError<U>`, if any exists
@@ -220,7 +221,7 @@ impl<T: 'static + Display + Debug> ChainError<T> {
     #[inline]
     pub fn find_chain_cause<U: Error + 'static>(&self) -> Option<&ChainError<U>> {
         self.iter()
-            .filter_map(Error::downcast_ref::<ChainError<U>>)
+            .filter_map(<dyn Error>::downcast_ref::<ChainError<U>>)
             .next()
     }
 
@@ -428,7 +429,7 @@ impl<U: 'static + Display + Debug> ChainErrorDown for ChainError<U> {
             #[allow(clippy::cast_ptr_alignment)]
             unsafe {
                 #[allow(trivial_casts)]
-                Some(&*(self as *const dyn Error as *const &ChainError<T>))
+                Some(*(self as *const dyn Error as *const &ChainError<T>))
             }
         } else {
             None

tests/test_iter.rs

@@ -18,13 +18,13 @@ fn test_iter() -> Result<(), Box<dyn Error + Send + Sync>> {
     let mut res = String::new();
 
     for e in err.iter() {
-        write!(res, "{}", e.to_string())?;
+        write!(res, "{}", e)?;
     }
     assert_eq!(res, "654321entity not found");
 
     let io_error: Option<&io::Error> = err
         .iter()
-        .filter_map(Error::downcast_ref::<io::Error>)
+        .filter_map(<dyn Error>::downcast_ref::<io::Error>)
         .next();
 
     assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);
@@ -50,7 +50,7 @@ fn test_iter() -> Result<(), Box<dyn Error + Send + Sync>> {
 
     let io_error: Option<&io::Error> = err
         .iter()
-        .filter_map(Error::downcast_ref::<io::Error>)
+        .filter_map(<dyn Error>::downcast_ref::<io::Error>)
         .next();
 
     assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);
@@ -88,7 +88,7 @@ fn test_root_cause() -> Result<(), Box<dyn Error + Send + Sync>> {
     let err = err.err().unwrap();
 
     let err: Option<&(dyn std::error::Error + 'static)> = err.root_cause();
-    let io_error: Option<&io::Error> = err.and_then(Error::downcast_ref::<io::Error>);
+    let io_error: Option<&io::Error> = err.and_then(<dyn Error>::downcast_ref::<io::Error>);
 
     assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);