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| author | Tyler Mandry <tmandry@gmail.com> | 2018-03-21 13:32:46 -0500 |
|---|---|---|
| committer | Tyler Mandry <tmandry@gmail.com> | 2018-03-21 13:32:46 -0500 |
| commit | b6934c91b23517c4e17d8016b6c46ffd0703eded (patch) | |
| tree | 7a1410a8946ae3da985ed3516a784e99ba5460aa | |
| parent | 2cdc7af41366182259a05435e325d7444653a3e8 (diff) | |
| download | rust-b6934c91b23517c4e17d8016b6c46ffd0703eded.tar.gz rust-b6934c91b23517c4e17d8016b6c46ffd0703eded.zip | |
termination_trait: Put examples in error help, not label
4 files changed, 18 insertions, 13 deletions
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs index 7e5dc02798d..8572c407714 100644 --- a/src/librustc/traits/error_reporting.rs +++ b/src/librustc/traits/error_reporting.rs @@ -585,20 +585,25 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> { trait_ref.to_predicate(), post_message) })); + let explanation = match obligation.cause.code { + ObligationCauseCode::MainFunctionType => { + "consider using `()`, or a `Result`".to_owned() + } + _ => { + format!("{}the trait `{}` is not implemented for `{}`", + pre_message, + trait_ref, + trait_ref.self_ty()) + } + }; + if let Some(ref s) = label { // If it has a custom "#[rustc_on_unimplemented]" // error message, let's display it as the label! err.span_label(span, s.as_str()); - err.help(&format!("{}the trait `{}` is not implemented for `{}`", - pre_message, - trait_ref, - trait_ref.self_ty())); + err.help(&explanation); } else { - err.span_label(span, - &*format!("{}the trait `{}` is not implemented for `{}`", - pre_message, - trait_ref, - trait_ref.self_ty())); + err.span_label(span, explanation); } if let Some(ref s) = note { // If it has a custom "#[rustc_on_unimplemented]" note, let's display it diff --git a/src/libstd/process.rs b/src/libstd/process.rs index a6aa3502f26..d5ac2d19e83 100644 --- a/src/libstd/process.rs +++ b/src/libstd/process.rs @@ -1443,7 +1443,7 @@ pub fn id() -> u32 { #[cfg_attr(not(test), lang = "termination")] #[unstable(feature = "termination_trait_lib", issue = "43301")] #[rustc_on_unimplemented = - "`main` can only return types like `()` that implement {Termination}, not `{Self}`"] + "`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. diff --git a/src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-i32.rs b/src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-i32.rs index 053d6bbf93a..2cf9fdcfb4d 100644 --- a/src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-i32.rs +++ b/src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-i32.rs @@ -10,6 +10,6 @@ fn main() -> i32 { //~^ ERROR `i32: std::process::Termination` is not satisfied -//~| NOTE `main` can only return types like `()` that implement std::process::Termination, not `i32` +//~| NOTE `main` can only return types that implement std::process::Termination, not `i32` 0 } diff --git a/src/test/ui/rfc-1937-termination-trait/termination-trait-main-wrong-type.stderr b/src/test/ui/rfc-1937-termination-trait/termination-trait-main-wrong-type.stderr index 24371c27742..211247757cb 100644 --- a/src/test/ui/rfc-1937-termination-trait/termination-trait-main-wrong-type.stderr +++ b/src/test/ui/rfc-1937-termination-trait/termination-trait-main-wrong-type.stderr @@ -2,9 +2,9 @@ error[E0277]: the trait bound `char: std::process::Termination` is not satisfied --> $DIR/termination-trait-main-wrong-type.rs:11:14 | LL | fn main() -> char { //~ ERROR - | ^^^^ `main` can only return types like `()` that implement std::process::Termination, not `char` + | ^^^^ `main` can only return types that implement std::process::Termination, not `char` | - = help: the trait `std::process::Termination` is not implemented for `char` + = help: consider using `()`, or a `Result` error: aborting due to previous error |