Add a custom error messagefield to exit

Author: morr0ne

src/lib.rs

@@ -16,13 +16,15 @@ pub type Result<T = (), E = Exit> = std::result::Result<T, E>;
 pub enum Exit {
     ArgError(sap::ParsingError),
     IoError(io::Error),
+    Custom(&'static str),
 }
 
 impl Debug for Exit {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             Self::ArgError(err) => Display::fmt(err, f),
             Self::IoError(err) => Display::fmt(err, f),
+            Self::Custom(err) => Display::fmt(err, f),
         }
     }
 }