From 2905f14b67def26ef003bf224886453cd20bf49a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Esteban=20K=C3=BCber?= <esteban@kuber.com.ar>
Date: Fri, 27 Dec 2019 20:09:33 -0800
Subject: [PATCH] Account for `type X = impl Trait;` in lifetime suggestion
---
.../borrow_check/diagnostics/region_errors.rs | 11 ++++++++---
.../multiple-lifetimes/error-handling.stderr | 2 +-
2 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/src/librustc_mir/borrow_check/diagnostics/region_errors.rs b/src/librustc_mir/borrow_check/diagnostics/region_errors.rs
index 8d534b6ec8e..1a1cf578f60 100644
--- a/src/librustc_mir/borrow_check/diagnostics/region_errors.rs
+++ b/src/librustc_mir/borrow_check/diagnostics/region_errors.rs
@@ -800,7 +800,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
// If there is a static predicate, then the only sensible suggestion is to replace
// fr with `'static`.
if has_static_predicate {
- diag.help(&format!("consider replacing `{}` with `{}`", fr_name, static_str,));
+ diag.help(&format!("consider replacing `{}` with `{}`", fr_name, static_str));
} else {
// Otherwise, we should suggest adding a constraint on the return type.
let span = infcx.tcx.def_span(*did);
@@ -810,7 +810,12 @@ impl<'tcx> RegionInferenceContext<'tcx> {
} else {
"'_".to_string()
};
-
+ let suggestion = if snippet.ends_with(";") {
+ // `type X = impl Trait;`
+ format!("{} + {};", &snippet[..snippet.len() - 1], suggestable_fr_name)
+ } else {
+ format!("{} + {}", snippet, suggestable_fr_name)
+ };
diag.span_suggestion(
span,
&format!(
@@ -818,7 +823,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
`{}`, add `{}` as a bound",
fr_name, suggestable_fr_name,
),
- format!("{} + {}", snippet, suggestable_fr_name),
+ suggestion,
Applicability::MachineApplicable,
);
}
diff --git a/src/test/ui/impl-trait/multiple-lifetimes/error-handling.stderr b/src/test/ui/impl-trait/multiple-lifetimes/error-handling.stderr
index 4c38f0a8a91..5957ecbdc5f 100644
--- a/src/test/ui/impl-trait/multiple-lifetimes/error-handling.stderr
+++ b/src/test/ui/impl-trait/multiple-lifetimes/error-handling.stderr
@@ -7,7 +7,7 @@ LL | fn foo<'a, 'b, 'c>(x: &'static i32, mut y: &'a i32) -> E<'b, 'c> {
= help: consider replacing `'a` with `'static`
help: to allow this `impl Trait` to capture borrowed data with lifetime `'a`, add `'a` as a bound
|
-LL | type E<'a, 'b> = impl Sized; + 'a
+LL | type E<'a, 'b> = impl Sized + 'a;
|
error: aborting due to previous error