diff options
Diffstat (limited to 'src/libstd')
| -rw-r--r-- | src/libstd/termination.rs | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/src/libstd/termination.rs b/src/libstd/termination.rs index a08d3dd2d52..5eeaa542b41 100644 --- a/src/libstd/termination.rs +++ b/src/libstd/termination.rs @@ -21,6 +21,8 @@ use libc; /// a successful execution. In case of a failure, `libc::EXIT_FAILURE` is returned. #[cfg_attr(not(stage0), lang = "termination")] #[unstable(feature = "termination_trait", issue = "0")] +#[rustc_on_unimplemented = + "`main` can only return types that implement {Termination}, not `{Self}`"] pub trait Termination { /// Is called to get the representation of the value as status code. /// This status code is returned to the operating system. |