From 1502713f994d595e4ae1ffbbe8ef3e373bbb11bc Mon Sep 17 00:00:00 2001
From: Aria Beingessner <a.beingessner@gmail.com>
Date: Mon, 6 Jun 2022 15:14:41 -0400
Subject: Impl Termination for Infallible and then make the Result impls of
 Termination into a blanket

This allows things like `Result<ExitCode, E>` to 'just work'
---
 library/std/src/process.rs | 37 +++++++++++++++----------------------
 1 file changed, 15 insertions(+), 22 deletions(-)

(limited to 'library/std/src')

diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index e733766741d..da8eee9030b 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -2140,16 +2140,6 @@ impl Termination for () {
     }
 }
 
-#[stable(feature = "termination_trait_lib", since = "1.61.0")]
-impl<E: fmt::Debug> Termination for Result<(), E> {
-    fn report(self) -> ExitCode {
-        match self {
-            Ok(()) => ().report(),
-            Err(err) => Err::<!, _>(err).report(),
-        }
-    }
-}
-
 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
 impl Termination for ! {
     fn report(self) -> ExitCode {
@@ -2158,28 +2148,31 @@ impl Termination for ! {
 }
 
 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
-impl<E: fmt::Debug> Termination for Result<!, E> {
+impl Termination for Infallible {
     fn report(self) -> ExitCode {
-        let Err(err) = self;
-        // Ignore error if the write fails, for example because stderr is
-        // already closed. There is not much point panicking at this point.
-        let _ = writeln!(io::stderr(), "Error: {err:?}");
-        ExitCode::FAILURE
+        match self {}
     }
 }
 
 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
-impl<E: fmt::Debug> Termination for Result<Infallible, E> {
+impl Termination for ExitCode {
+    #[inline]
     fn report(self) -> ExitCode {
-        let Err(err) = self;
-        Err::<!, _>(err).report()
+        self
     }
 }
 
 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
-impl Termination for ExitCode {
-    #[inline]
+impl<T: Termination, E: fmt::Debug> Termination for Result<T, E> {
     fn report(self) -> ExitCode {
-        self
+        match self {
+            Ok(val) => val.report(),
+            Err(err) => {
+                // Ignore error if the write fails, for example because stderr is
+                // already closed. There is not much point panicking at this point.
+                let _ = writeln!(io::stderr(), "Error: {err:?}");
+                ExitCode::FAILURE
+            }
+        }
     }
 }
-- 
cgit 1.4.1-3-g733a5