From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 16 Oct 2020 22:23:08 +0000 (+0100)
Subject: get rid of ! type
X-Git-Tag: otter-0.2.0~634
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=7c3256c84842ab5e420b38f08838c234c6f5ba54;p=otter.git

get rid of ! type

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/src/cmdlistener.rs b/src/cmdlistener.rs
index 9a7f7d32..76b8abf2 100644
--- a/src/cmdlistener.rs
+++ b/src/cmdlistener.rs
@@ -170,7 +170,7 @@ fn execute_game_insn(cs: &CommandStream,
         .unwrap_or("");
       let tz = match Timezone::from_str(timezone) {
         Ok(tz) => tz,
-        Err(x) => x, // x is of type !
+        Err(x) => match x { },
       };
       let (player, logentry) = ig.player_new(pl.st, tz, logentry)?;
       (U{ pcs: vec![],
diff --git a/src/imports.rs b/src/imports.rs
index 53b6f993..dcd5754f 100644
--- a/src/imports.rs
+++ b/src/imports.rs
@@ -126,7 +126,9 @@ pub use nix::unistd::Uid;
 
 pub fn default<T:Default>() -> T { Default::default() }
 
+#[derive(Debug,Copy,Clone)]
 pub enum Impossible { }
+display_as_debug!(Impossible);
 
 pub type E = anyhow::Error;
 pub type AE = anyhow::Error;
diff --git a/src/lib.rs b/src/lib.rs
index d095695a..96163a0a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 // There is NO WARRANTY.
 
-#![feature(never_type)]
 #![feature(proc_macro_hygiene, decl_macro)]
 #![feature(slice_strip)]
 
diff --git a/src/tz.rs b/src/tz.rs
index 04c7e20d..39f958cf 100644
--- a/src/tz.rs
+++ b/src/tz.rs
@@ -43,8 +43,8 @@ type MemoTable = Option<HashMap<String, Timezone>>;
 static MEMO: RwLock<MemoTable> = const_rwlock(None);
 
 impl FromStr for Timezone {
-  type Err = !;
-  #[throws(!)]
+  type Err = Impossible;
+  #[throws(Impossible)]
   fn from_str(name: &str) -> Self {
     if name.is_empty() { return default() }