From 020084509d497b32c323f3bd800a9b204c2ca125 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 18 Apr 2022 11:42:26 +0100
Subject: [PATCH] Provide is_default() function

We're going to use this to elide some fields from the game save state.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 Cargo.lock     | 1 +
 Cargo.toml     | 1 +
 cli/otter.rs   | 1 -
 src/prelude.rs | 1 +
 src/utils.rs   | 2 ++
 5 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1389d223..cec429b9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2648,6 +2648,7 @@ dependencies = [
  "chrono",
  "chrono-tz",
  "console",
+ "const-default",
  "crossbeam-utils",
  "delegate",
  "derive-into-owned",
diff --git a/Cargo.toml b/Cargo.toml
index 548889a5..ab5799d2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -89,6 +89,7 @@ xmlparser = "0.13"
 zip="0.6"
 
 async-condvar-fair = { version="0.2", features=["parking_lot_0_12"] }
+const-default = { version="1",    features=["derive"      ] }
 enum-map     = { version="2"    , features=["serde"       ] }
 flexi_logger = { version="0.22" , features=["specfile"    ] }
 image = { version = "0.24", default-features=false, features=["jpeg","png"] }
diff --git a/cli/otter.rs b/cli/otter.rs
index 0c9ada05..89657b9a 100644
--- a/cli/otter.rs
+++ b/cli/otter.rs
@@ -22,7 +22,6 @@ pub use std::rc::Rc;
 
 pub use argparse::{self,ArgumentParser,action::{TypedAction,ParseResult}};
 pub use argparse::action::{Action,IFlagAction,IArgAction};
-pub use const_default::ConstDefault;
 pub use derive_more::Display;
 
 pub use otter::prelude::*;
diff --git a/src/prelude.rs b/src/prelude.rs
index 05de7123..f62e4ba7 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -58,6 +58,7 @@ pub use arrayvec::ArrayVec;
 pub use boolinator::Boolinator as _;
 pub use byteorder::{BigEndian, LittleEndian, ReadBytesExt, WriteBytesExt};
 pub use cast_trait_object::{dyn_upcast, DynCastExt};
+pub use const_default::ConstDefault;
 pub use delegate::delegate;
 pub use derive_into_owned::IntoOwned;
 pub use derive_more::*;
diff --git a/src/utils.rs b/src/utils.rs
index c04918b1..f12ec31f 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -622,6 +622,8 @@ impl<I,T> IndexVec<I,T> where I: index_vec::Idx {
   }
 }
 
+pub fn is_default<T: ConstDefault + Eq>(t: &T) -> bool { t == &T::DEFAULT }
+
 #[derive(Debug)]
 pub struct AnyhowDisplay<'a>(pub &'a anyhow::Error);
 impl Display for AnyhowDisplay<'_> {
-- 
2.30.2