From 8436120d124c0c148ef68b51dac3c31ed27527df Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 31 Jan 2021 23:07:32 +0000
Subject: [PATCH] hidden: Document the convention about last face

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 src/gamestate.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/gamestate.rs b/src/gamestate.rs
index d50baaed..1a308d52 100644
--- a/src/gamestate.rs
+++ b/src/gamestate.rs
@@ -122,6 +122,7 @@ pub struct UoDescription {
 
 #[typetag::serde]
 pub trait Piece: Outline + Send + Debug {
+  /// by convention, occult face is nfaces-1
   fn nfaces(&self) -> RawFaceId;
 
   #[throws(InternalError)]
-- 
2.30.2