From 02d0a8bbcf0a64339e4279c4ddb4841189ba5069 Mon Sep 17 00:00:00 2001 From: Manish Goregaokar Date: Mon, 12 Jan 2015 01:35:16 +0530 Subject: [PATCH] docs --- src/doc/reference.md | 7 +++++++ src/test/compile-fail/on-unimplemented-bad-anno.rs | 3 +++ 2 files changed, 10 insertions(+) diff --git a/src/doc/reference.md b/src/doc/reference.md index 2486466c8696d..62b922ea4beac 100644 --- a/src/doc/reference.md +++ b/src/doc/reference.md @@ -2117,6 +2117,13 @@ macro scope. destructors from being run twice. Destructors might be run multiple times on the same object with this attribute. - `doc` - Doc comments such as `/// foo` are equivalent to `#[doc = "foo"]`. +- `rustc_on_unimplemented` - Write a custom note to be shown along with the error + when the trait is found to be unimplemented on a type. + You may use format arguments like `{T}`, `{A}` to correspond to the + types at the point of use corresponding to the type parameters of the + trait of the same name. `{Self}` will be replaced with the type that is supposed + to implement the trait but doesn't. To use this, the `on_unimplemented` feature gate + must be enabled. ### Conditional compilation diff --git a/src/test/compile-fail/on-unimplemented-bad-anno.rs b/src/test/compile-fail/on-unimplemented-bad-anno.rs index 3bd3f517dbccd..dda534cc489b5 100644 --- a/src/test/compile-fail/on-unimplemented-bad-anno.rs +++ b/src/test/compile-fail/on-unimplemented-bad-anno.rs @@ -29,6 +29,9 @@ trait BadAnnotation1 {} //~^ ERROR there is no type parameter C on trait BadAnnotation2 trait BadAnnotation2 {} +#[rustc_on_unimplemented = "Unimplemented trait error on `{Self}` with params `<{A},{B},{}>`"] +//~^ only named substitution parameters are allowed +trait BadAnnotation3 {} pub fn main() { }