From 53c2560a1fc366936ea0a635f9c463745118d5af Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 21 Feb 2021 23:26:28 +0000
Subject: [PATCH] Introduce deref_to_field!

NFC

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 apitest.rs            |  3 +++
 src/utils.rs          | 10 ++++++++++
 wdriver.rs            | 10 ----------
 wdriver/wdt-hand.rs   |  2 +-
 wdriver/wdt-simple.rs |  2 +-
 5 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/apitest.rs b/apitest.rs
index 0ecb47ab..cdd09ffe 100644
--- a/apitest.rs
+++ b/apitest.rs
@@ -55,6 +55,7 @@ pub use otter::ensure_eq;
 pub use otter::commands::{MgmtCommand, MgmtResponse};
 pub use otter::commands::{MgmtGameInstruction, MgmtGameResponse};
 pub use otter::commands::{MgmtGameUpdateMode};
+pub use otter::deref_to_field;
 pub use otter::gamestate::{self, Generation, PlayerId};
 pub use otter::global::InstanceName;
 pub use otter::mgmtchannel::MgmtChannel;
@@ -127,6 +128,8 @@ pub struct Instance(pub InstanceName);
 
 // ==================== Facilities for tests ====================
 
+impl AsRef<Opts> for Opts { fn as_ref(&self) -> &Opts { self } }
+
 // -------------------- Substition --------------------
 
 pub trait Substitutor {
diff --git a/src/utils.rs b/src/utils.rs
index 47e537ed..5354639e 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -273,3 +273,13 @@ pub fn toml_merge<'u,
     }
   }
 }
+
+#[macro_export]
+macro_rules! deref_to_field {
+  {$outer:ident, $inner:ty, $field:ident} => {
+    impl Deref for $outer {
+      type Target = $inner;
+      fn deref(&self) -> &$inner { &self.$field }
+    }
+  }
+}
diff --git a/wdriver.rs b/wdriver.rs
index 1fc055a0..8eb97c6e 100644
--- a/wdriver.rs
+++ b/wdriver.rs
@@ -365,16 +365,6 @@ fn check_window_name_sanity(name: &str) -> &str {
   name
 }
 
-#[macro_export]
-macro_rules! ctx_with_setup {
-  {$ctx:ident} => {
-    impl Deref for $ctx {
-      type Target = self::Setup;
-      fn deref(&self) -> &self::Setup { &self.su }
-    }
-  }
-}
-
 impl Setup {
   pub fn want_test(&mut self, tname: &str) -> bool {
     self.wanted_tests.wantp(tname)
diff --git a/wdriver/wdt-hand.rs b/wdriver/wdt-hand.rs
index 6422e3ec..981f47b4 100644
--- a/wdriver/wdt-hand.rs
+++ b/wdriver/wdt-hand.rs
@@ -9,7 +9,7 @@ struct Ctx {
   alice: Window,
   bob: Window,
 }
-ctx_with_setup!{Ctx}
+deref_to_field!{Ctx, Setup, su}
 
 const HAND: &str = "6.1";
 const ALICE: &str = "1#1";
diff --git a/wdriver/wdt-simple.rs b/wdriver/wdt-simple.rs
index 13a9d2e8..a6e76731 100644
--- a/wdriver/wdt-simple.rs
+++ b/wdriver/wdt-simple.rs
@@ -10,7 +10,7 @@ struct Ctx {
   bob: Window,
   spec: GameSpec,
 }
-ctx_with_setup!{Ctx}
+deref_to_field!{Ctx, Setup, su}
 
 impl Ctx {
   #[throws(AE)]
-- 
2.30.2