Added regression tests for ambiguous associated item error fix

tests/from_str.rs

@@ -17,6 +17,12 @@ struct Point1D {
     x: i32,
 }
 
+/// Making sure that `FromStr` does not trigger an ambiguous associated item error for `Err`.
+#[derive(FromStr)]
+enum EnumWithErr {
+    Err,
+}
+
 #[derive(Debug, FromStr, PartialEq, Eq)]
 enum EnumNoFields {
     Foo,
@@ -44,4 +50,4 @@ fn enum_test_case_sensitive() {
         "baz".parse::<EnumNoFields>().unwrap_err().to_string(),
         "Invalid `EnumNoFields` string representation",
     );
-}
+}

tests/try_from.rs

@@ -3,6 +3,14 @@
 
 use derive_more::TryFrom;
 
+/// Making sure that `TryFrom` does not trigger an ambiguous associated item error for `Error`.
+#[derive(TryFrom)]
+#[try_from(repr)]
+#[repr(u8)]
+enum EnumWithError {
+    Error,
+}
+
 #[test]
 fn test_with_repr() {
     #[derive(TryFrom, Clone, Copy, Debug, Eq, PartialEq)]

tests/try_into.rs

@@ -47,6 +47,16 @@ enum Foo<'lt: 'static, T: Clone, const X: usize> {
     X(Wrapper<'lt, X, T>),
 }
 
+enum EnumWithError {
+    Error,
+}
+
+/// Making sure that `TryInto` does not trigger an ambiguous associated item error for `Error`.
+#[derive(TryInto)]
+enum EnumIntoEnumWithError {
+    Foo(EnumWithError),
+}
+
 #[test]
 fn test_try_into() {
     let mut i = MixedInts::SmallInt(42);