diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs index a38840552c2..2e84aff4985 100644 --- a/src/librustc_typeck/check/compare_method.rs +++ b/src/librustc_typeck/check/compare_method.rs @@ -788,16 +788,18 @@ pub fn compare_const_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, trait", trait_c.name); - // Add a label to the Span containing just the type of the item - let trait_c_node_id = tcx.hir.as_local_node_id(trait_c.def_id).unwrap(); - let trait_c_span = match tcx.hir.expect_trait_item(trait_c_node_id).node { - TraitItemKind::Const(ref ty, _) => ty.span, - _ => bug!("{:?} is not a trait const", trait_c), - }; + let trait_c_node_id = tcx.hir.as_local_node_id(trait_c.def_id); + let trait_c_span = trait_c_node_id.map(|trait_c_node_id| { + // Add a label to the Span containing just the type of the const + match tcx.hir.expect_trait_item(trait_c_node_id).node { + TraitItemKind::Const(ref ty, _) => ty.span, + _ => bug!("{:?} is not a trait const", trait_c), + } + }); infcx.note_type_err(&mut diag, &cause, - Some((trait_c_span, format!("type in trait"))), + trait_c_span.map(|span| (span, format!("type in trait"))), Some(infer::ValuePairs::Types(ExpectedFound { expected: trait_ty, found: impl_ty, diff --git a/src/test/compile-fail/auxiliary/issue_41549.rs b/src/test/compile-fail/auxiliary/issue_41549.rs new file mode 100644 index 00000000000..77b203997b4 --- /dev/null +++ b/src/test/compile-fail/auxiliary/issue_41549.rs @@ -0,0 +1,15 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![feature(associated_consts)] + +pub trait Trait { + const CONST: u32; +} diff --git a/src/test/compile-fail/issue-41549.rs b/src/test/compile-fail/issue-41549.rs new file mode 100644 index 00000000000..c4aab4bcabf --- /dev/null +++ b/src/test/compile-fail/issue-41549.rs @@ -0,0 +1,23 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// aux-build:issue_41549.rs + +#![feature(associated_consts)] + +extern crate issue_41549; + +struct S; + +impl issue_41549::Trait for S { + const CONST: () = (); //~ ERROR incompatible type for trait +} + +fn main() {}