X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flibrustc%2Ftraits%2Fon_unimplemented.rs;h=b39c00a56e349ad13c5933b9f6e55c9f69d1b176;hb=f49f38871389041671cc710a044e8360091840a3;hp=c1c814f9b0371218a0415b78d2b8479cd394cd4e;hpb=eec3a9c4af5067c37f5b681599a48b4e21098260;p=rust.git

diff --git a/src/librustc/traits/on_unimplemented.rs b/src/librustc/traits/on_unimplemented.rs
index c1c814f9b03..b39c00a56e3 100644
--- a/src/librustc/traits/on_unimplemented.rs
+++ b/src/librustc/traits/on_unimplemented.rs
@@ -248,6 +248,8 @@ fn verify(
                     Position::ArgumentNamed(s) if s == sym::from_method => (),
                     // `{from_desugaring}` is allowed
                     Position::ArgumentNamed(s) if s == sym::from_desugaring => (),
+                    // `{ItemContext}` is allowed
+                    Position::ArgumentNamed(s) if s == sym::item_context => (),
                     // So is `{A}` if A is a type parameter
                     Position::ArgumentNamed(s) => match generics.params.iter().find(|param| {
                         param.name == s
@@ -296,6 +298,7 @@ pub fn format(
 
         let s = self.0.as_str();
         let parser = Parser::new(&s, None, vec![], false);
+        let item_context = (options.get(&sym::item_context)).unwrap_or(&empty_string);
         parser.map(|p|
             match p {
                 Piece::String(s) => s,
@@ -311,6 +314,8 @@ pub fn format(
                             } else if s == sym::from_desugaring || s == sym::from_method {
                                 // don't break messages using these two arguments incorrectly
                                 &empty_string
+                            } else if s == sym::item_context {
+                                &item_context
                             } else {
                                 bug!("broken on_unimplemented {:?} for {:?}: \
                                       no argument matching {:?}",