From ac3290e8d949448193014c85096f8772db331d46 Mon Sep 17 00:00:00 2001
From: Esteban Küber <esteban@kuber.com.ar>
Date: Sun, 17 Mar 2019 22:42:51 -0700
Subject: Add suggestion to use `&*var` when `&str: From<String>` is expected

---
 src/libcore/convert.rs | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'src/libcore')

diff --git a/src/libcore/convert.rs b/src/libcore/convert.rs
index 774d648558b..cb574a53dbc 100644
--- a/src/libcore/convert.rs
+++ b/src/libcore/convert.rs
@@ -352,6 +352,12 @@ pub trait Into<T>: Sized {
 /// [`from`]: trait.From.html#tymethod.from
 /// [book]: ../../book/ch09-00-error-handling.html
 #[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_on_unimplemented(
+    on(
+        all(_Self="&str", T="std::string::String"),
+        note="you can coerce a `{T}` into a `{Self}` by writing `&*variable`"
+    )
+)]
 pub trait From<T>: Sized {
     /// Performs the conversion.
     #[stable(feature = "rust1", since = "1.0.0")]
-- 
cgit 1.4.1-3-g733a5


From e929d19edc99e5eb7af319709247470cff99719b Mon Sep 17 00:00:00 2001
From: Esteban Küber <esteban@kuber.com.ar>
Date: Fri, 22 Mar 2019 20:38:09 -0700
Subject: review comments

---
 src/libcore/convert.rs                  | 2 +-
 src/test/ui/suggestions/into-str.stderr | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

(limited to 'src/libcore')

diff --git a/src/libcore/convert.rs b/src/libcore/convert.rs
index cb574a53dbc..d36de3bbe86 100644
--- a/src/libcore/convert.rs
+++ b/src/libcore/convert.rs
@@ -355,7 +355,7 @@ pub trait Into<T>: Sized {
 #[rustc_on_unimplemented(
     on(
         all(_Self="&str", T="std::string::String"),
-        note="you can coerce a `{T}` into a `{Self}` by writing `&*variable`"
+        note="to coerce a `{T}` into a `{Self}`, use `&*` as a prefix",
     )
 )]
 pub trait From<T>: Sized {
diff --git a/src/test/ui/suggestions/into-str.stderr b/src/test/ui/suggestions/into-str.stderr
index f341d363702..3e28700ce95 100644
--- a/src/test/ui/suggestions/into-str.stderr
+++ b/src/test/ui/suggestions/into-str.stderr
@@ -4,7 +4,7 @@ error[E0277]: the trait bound `&str: std::convert::From<std::string::String>` is
 LL |     foo(String::new());
    |     ^^^ the trait `std::convert::From<std::string::String>` is not implemented for `&str`
    |
-   = note: you can coerce a `std::string::String` into a `&str` by writing `&*variable`
+   = note: to coerce a `std::string::String` into a `&str`, use `&*` as a prefix
    = note: required because of the requirements on the impl of `std::convert::Into<&str>` for `std::string::String`
 note: required by `foo`
   --> $DIR/into-str.rs:1:1
-- 
cgit 1.4.1-3-g733a5