From 345dd339426a3280a429846ccb9c2122f9e38c32 Mon Sep 17 00:00:00 2001
From: bluss <bluss@users.noreply.github.com>
Date: Sun, 30 Jul 2017 15:09:02 +0200
Subject: [PATCH] FEAT: Refactor errors. Insert is either out of bounds or
 capacity error

---
 src/errors.rs  | 32 +++++++++++++++++++-------------
 src/lib.rs     | 12 ++++++------
 tests/tests.rs | 10 ++++++----
 3 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/src/errors.rs b/src/errors.rs
index 168f37b..134926a 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -51,15 +51,15 @@ impl<T> fmt::Debug for CapacityError<T> {
 }
 
 pub enum InsertError<T> {
-    Full(T),
-    OutOfBounds,
+    Capacity(CapacityError<T>),
+    OutOfBounds(OutOfBoundsError),
 }
 
 impl<T> InsertError<T> {
     fn description(&self) -> &'static str {
         match *self {
-            InsertError::Full(_) => "ArrayVec is already at full capacity",
-            InsertError::OutOfBounds => "index is out of bounds",
+            InsertError::Capacity(_) => "ArrayVec is already at full capacity",
+            InsertError::OutOfBounds(_) => "index is out of bounds",
         }
     }
 }
@@ -70,6 +70,12 @@ impl<T: Any> Error for InsertError<T> {
     fn description(&self) -> &str {
         self.description()
     }
+    fn cause(&self) -> Option<&Error> {
+        match *self {
+            InsertError::Capacity(ref e) => Some(e as &Error),
+            InsertError::OutOfBounds(ref e) => Some(e as &Error),
+        }
+    }
 }
 
 impl<T> fmt::Display for InsertError<T> {
@@ -81,20 +87,20 @@ impl<T> fmt::Display for InsertError<T> {
 impl<T> fmt::Debug for InsertError<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            InsertError::Full(_) => write!(f, "InsertError::Full: ")?,
-            InsertError::OutOfBounds => write!(f, "InsertError::OutOfBounds: ")?,
+            InsertError::Capacity(_) => write!(f, "InsertError::Capacity: ")?,
+            InsertError::OutOfBounds(_) => write!(f, "InsertError::OutOfBounds: ")?,
         }
         write!(f, "{}", self.description())
     }
 }
 
-pub struct RemoveError {
+pub struct OutOfBoundsError {
     _priv: ()
 }
 
-impl RemoveError {
+impl OutOfBoundsError {
     pub(crate) fn new() -> Self {
-        RemoveError { _priv: () }
+        OutOfBoundsError { _priv: () }
     }
 
     fn description(&self) -> &'static str {
@@ -104,20 +110,20 @@ impl RemoveError {
 
 #[cfg(feature="std")]
 /// Requires `features="std"`.
-impl Error for RemoveError {
+impl Error for OutOfBoundsError {
     fn description(&self) -> &str {
         self.description()
     }
 }
 
-impl fmt::Display for RemoveError {
+impl fmt::Display for OutOfBoundsError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{}", self.description())
     }
 }
 
-impl fmt::Debug for RemoveError {
+impl fmt::Debug for OutOfBoundsError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "RemoveError: {}", self.description())
+        write!(f, "OutOfBoundsError: {}", self.description())
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 30d8c9d..8dbbadd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -277,10 +277,10 @@ impl<A: Array> ArrayVec<A> {
     /// ```
     pub fn try_insert(&mut self, index: usize, element: A::Item) -> Result<(), InsertError<A::Item>> {
         if self.len() == self.capacity() {
-            return Err(InsertError::Full(element));
+            return Err(InsertError::Capacity(CapacityError::new(element)));
         }
         if index > self.len() {
-            return Err(InsertError::OutOfBounds);
+            return Err(InsertError::OutOfBounds(OutOfBoundsError::new()));
         }
         let len = self.len();
 
@@ -365,10 +365,10 @@ impl<A: Array> ArrayVec<A> {
     ///
     /// assert!(array.try_swap_remove(10).is_err());
     /// ```
-    pub fn try_swap_remove(&mut self, index: usize) -> Result<A::Item, RemoveError> {
+    pub fn try_swap_remove(&mut self, index: usize) -> Result<A::Item, OutOfBoundsError> {
         let len = self.len();
         if index >= len {
-            return Err(RemoveError::new())
+            return Err(OutOfBoundsError::new())
         }
         self.swap(index, len - 1);
         self.pop().ok_or_else(|| panic!())
@@ -411,9 +411,9 @@ impl<A: Array> ArrayVec<A> {
     /// assert!(array.try_remove(2).is_err());
     /// assert!(array.try_remove(10).is_err());
     /// ```
-    pub fn try_remove(&mut self, index: usize) -> Result<A::Item, RemoveError> {
+    pub fn try_remove(&mut self, index: usize) -> Result<A::Item, OutOfBoundsError> {
         if index >= self.len() {
-            Err(RemoveError::new())
+            Err(OutOfBoundsError::new())
         } else {
             self.drain(index..index + 1).next().ok_or_else(|| panic!())
         }
diff --git a/tests/tests.rs b/tests/tests.rs
index 8e73a90..19b95c2 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -4,6 +4,7 @@ extern crate arrayvec;
 use arrayvec::ArrayVec;
 use arrayvec::ArrayString;
 use std::mem;
+use arrayvec::errors::InsertError;
 
 use std::collections::HashMap;
 
@@ -226,18 +227,19 @@ fn test_insert() {
     let mut v = ArrayVec::<[_; 3]>::new();
     v.insert(0, 0);
     v.insert(1, 1);
-    v.insert(2, 2);
     let ret1 = v.try_insert(3, 3);
+    assert_matches!(ret1, Err(InsertError::OutOfBounds(_)));
+    assert_eq!(&v[..], &[0, 1]);
+    v.insert(2, 2);
     assert_eq!(&v[..], &[0, 1, 2]);
-    assert_matches!(ret1, Err(_));
 
     let ret2 = v.try_insert(1, 9);
     assert_eq!(&v[..], &[0, 1, 2]);
     assert_matches!(ret2, Err(_));
 
     let mut v = ArrayVec::from([2]);
-    assert_matches!(v.try_insert(1, 1), Err(_));
-    assert_matches!(v.try_insert(2, 1), Err(_));
+    assert_matches!(v.try_insert(1, 1), Err(InsertError::Capacity(_)));
+    assert_matches!(v.try_insert(2, 1), Err(InsertError::Capacity(_)));
 }
 
 #[test]