From 58c30675741c85d728e499fe9215a084d5520db2 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 27 Sep 2020 01:25:20 +0100
Subject: [PATCH] abolish two unwraps

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/api.rs   | 7 +++----
 src/error.rs | 4 ++--
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/api.rs b/src/api.rs
index ea2ef9f8..2078fb2a 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -108,8 +108,7 @@ fn api_piece_op<O: ApiPieceOp>(form : Json<ApiPiece<O>>)
 
   match (||{
     let p = g_pieces.get(piece).ok_or(OnlineError::PieceGone)?;
-    let pc = gs.pieces.byid_mut(piece)
-      .map_err(|()| OnlineError::PieceGone)?;
+    let pc = gs.pieces.byid_mut(piece)?;
 
     let q_gen = form.gen;
     let u_gen =
@@ -166,8 +165,8 @@ impl ApiPieceOp for ApiPieceGrab {
   fn op(&self, gs: &mut GameState, player: PlayerId, piece: PieceId,
         p: &dyn Piece, lens: &dyn Lens)
         -> (PieceUpdateOp<()>, Vec<LogEntry>) {
-    let pl = gs.players.byid(player).unwrap();
-    let pc = gs.pieces.byid_mut(piece).unwrap();
+    let pl = gs.players.byid(player)?;
+    let pc = gs.pieces.byid_mut(piece)?;
 
     if pc.held.is_some() { throw!(OnlineError::PieceHeld) }
     pc.held = Some(player);
diff --git a/src/error.rs b/src/error.rs
index efb92a76..b45d88ae 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -136,8 +136,8 @@ impl<T> IdForById for T where T : AccessId {
 }
 
 impl IdForById for PieceId {
-  type Error = ();
-  const ERROR : () = ();
+  type Error = OE;
+  const ERROR : OE = OE::PieceGone;
 }
 
 #[macro_export]
-- 
2.30.2