added hidden nonexaustive variant

fixes rust-lang-deprecated#182

Author: tinaun

CHANGELOG.md

@@ -3,6 +3,7 @@
 - [Add a new method for `Error`: `chain_err`.](https://github.com/brson/error-chain/pull/141)
 - [Allow `chain_err` to be used on `Option<T>`](https://github.com/brson/error-chain/pull/156)
 - [Add support for creating an error chain on boxed trait errors (`Box<Error>`)](https://github.com/brson/error-chain/pull/156)
+- [Generated `ErrorKind` enums are now nonexaustive](https://github.com/brson/error-chain/pull/193)
 
 # 0.10.0
 
@@ -15,7 +16,7 @@
 
 # 0.8.1
 
-- Add crates.io categorie.
+- Add crates.io category.
 
 # 0.8.0
 

src/lib.rs

@@ -331,7 +331,9 @@
 //!
 //! error-chain error variants are matched with simple patterns.
 //! `Error` is a tuple struct and its first field is the `ErrorKind`,
-//! making dispatching on error kinds relatively compact:
+//! making dispatching on error kinds relatively compact. Note that
+//! because `ErrorKind` is open and always extensible, you always need
+//! to handle the unknown case: 
 //!
 //! ```
 //! # #[macro_use] extern crate error_chain;
@@ -348,6 +350,7 @@
 //! match Error::from("error!") {
 //!     Error(ErrorKind::InvalidToolchainName(_), _) => { }
 //!     Error(ErrorKind::Msg(_), _) => { }
+//!     _ => { }
 //! }
 //! # }
 //! ```

src/quick_error.rs

@@ -200,6 +200,9 @@ macro_rules! quick_error {
                 $(#[$imeta])*
                 $iitem $(($( $ttyp ),*))* $({$( $svar: $styp ),*})*,
             )*
+
+            #[doc(hidden)]
+            __Nonexhaustive {}
         }
     };
     // Private enum (Queue Empty)
@@ -278,6 +281,8 @@ macro_rules! quick_error {
                             display_fn(self, fmt)
                         }
                     )*
+
+                    _ => Ok(())
                 }
             }
         }
@@ -325,6 +330,8 @@ macro_rules! quick_error {
                                 {$( $funcs )*})
                         }
                     )*
+
+                    _ => "",
                 }
             }
         }

tests/tests.rs

@@ -490,7 +490,8 @@ fn error_patterns() {
 
     // Tuples look nice when matching errors
     match Error::from("Test") {
-        Error(ErrorKind::Msg(_), _) => {}
+        Error(ErrorKind::Msg(_), _) => {},
+        _ => {},
     }
 }