diff --git a/src/librustc_typeck/check/demand.rs b/src/librustc_typeck/check/demand.rs index 08d8dd2e498b6..aee64ad3b550c 100644 --- a/src/librustc_typeck/check/demand.rs +++ b/src/librustc_typeck/check/demand.rs @@ -264,9 +264,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { (&ty::TyStr, &ty::TySlice(arr)) if arr == self.tcx.types.u8 => { if let hir::ExprLit(_) = expr.node { if let Ok(src) = cm.span_to_snippet(sp) { - return Some((sp, - "consider removing the leading `b`", - src[1..].to_string())); + if src.starts_with("b\"") { + return Some((sp, + "consider removing the leading `b`", + src[1..].to_string())); + } } } }, @@ -274,9 +276,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { (&ty::TySlice(arr), &ty::TyStr) if arr == self.tcx.types.u8 => { if let hir::ExprLit(_) = expr.node { if let Ok(src) = cm.span_to_snippet(sp) { - return Some((sp, - "consider adding a leading `b`", - format!("b{}", src))); + if src.starts_with("\"") { + return Some((sp, + "consider adding a leading `b`", + format!("b{}", src))); + } } } } diff --git a/src/test/ui/suggestions/issue-48364.rs b/src/test/ui/suggestions/issue-48364.rs new file mode 100644 index 0000000000000..82cb722a65600 --- /dev/null +++ b/src/test/ui/suggestions/issue-48364.rs @@ -0,0 +1,16 @@ +// Copyright 2018 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. + +fn foo() -> bool { + b"".starts_with(stringify!(foo)) + //~^ ERROR mismatched types +} + +fn main() {} diff --git a/src/test/ui/suggestions/issue-48364.stderr b/src/test/ui/suggestions/issue-48364.stderr new file mode 100644 index 0000000000000..b420654a32d8c --- /dev/null +++ b/src/test/ui/suggestions/issue-48364.stderr @@ -0,0 +1,12 @@ +error[E0308]: mismatched types + --> $DIR/issue-48364.rs:12:21 + | +LL | b"".starts_with(stringify!(foo)) + | ^^^^^^^^^^^^^^^ expected slice, found str + | + = note: expected type `&[u8]` + found type `&'static str` + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0308`.