Use Error in TryFrom

Author: ginnyTheCat

src/error.rs

@@ -75,6 +75,7 @@ pub enum Error {
     IntConversion(TryFromIntError),
     InvalidUtf8,
     UnexpectedNullPtr,
+    UnknownEnumVariant,
 }
 
 impl fmt::Display for Error {
@@ -91,6 +92,7 @@ impl fmt::Display for Error {
                 f,
                 "An FFI function call returned a null ptr when we expected a non-null ptr"
             ),
+            Error::UnknownEnumVariant => write!(f, "unknown enum variant provided"),
         }
     }
 }

src/lib.rs

@@ -257,13 +257,13 @@ macro_rules! from_enum {
         }
 
         impl TryFrom<$c_type> for $name {
-            type Error = ();
+            type Error = Error;
 
             #[allow(non_upper_case_globals)]
             fn try_from(value: $c_type) -> Result<Self, Self::Error> {
                 match value {
                     $($value => Ok(Self::$field),)*
-                    _ => Err(())
+                    _ => Err(Error::UnknownEnumVariant)
                 }
             }
         }