From b002da84fd32ab228020b18d58a9c11ee89ed071 Mon Sep 17 00:00:00 2001
From: Tony Arcieri <bascule@gmail.com>
Date: Wed, 7 Feb 2024 18:10:54 -0700
Subject: [PATCH] Use `ConstZero` trait from `num_traits`

Added in rust-num/num-traits#303
---
 Cargo.lock                      |  4 ++--
 Cargo.toml                      |  2 +-
 src/modular/const_monty_form.rs | 12 ++++++++++++
 src/traits.rs                   | 12 ++----------
 4 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5b494c45..a562db9d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -424,9 +424,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.17"
+version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
+checksum = "da0df0e5185db44f69b44f26786fe401b6c293d1907744beaa7fa62b2e5a517a"
 dependencies = [
  "autocfg",
  "libm",
diff --git a/Cargo.toml b/Cargo.toml
index 9c3f8ce6..b191dd4c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,7 +22,7 @@ subtle = { version = "2.5", default-features = false }
 # optional dependencies
 der = { version = "0.7", optional = true, default-features = false }
 hybrid-array = { version = "0.2.0-rc.4", optional = true }
-num-traits = { version = "0.2", default-features = false }
+num-traits = { version = "0.2.18", default-features = false }
 rand_core = { version = "0.6.4", optional = true }
 rlp = { version = "0.5", optional = true, default-features = false }
 serdect = { version = "0.2", optional = true, default-features = false }
diff --git a/src/modular/const_monty_form.rs b/src/modular/const_monty_form.rs
index 3e1f52e7..6c3c4c6c 100644
--- a/src/modular/const_monty_form.rs
+++ b/src/modular/const_monty_form.rs
@@ -185,6 +185,18 @@ impl<MOD: ConstMontyParams<LIMBS>, const LIMBS: usize> ConstZero for ConstMontyF
     const ZERO: Self = Self::ZERO;
 }
 
+impl<MOD: ConstMontyParams<LIMBS>, const LIMBS: usize> num_traits::Zero
+    for ConstMontyForm<MOD, LIMBS>
+{
+    fn zero() -> Self {
+        Self::ZERO
+    }
+
+    fn is_zero(&self) -> bool {
+        self.ct_eq(&Self::ZERO).into()
+    }
+}
+
 #[cfg(feature = "rand_core")]
 impl<MOD, const LIMBS: usize> Random for ConstMontyForm<MOD, LIMBS>
 where
diff --git a/src/traits.rs b/src/traits.rs
index 2780226a..1dde9261 100644
--- a/src/traits.rs
+++ b/src/traits.rs
@@ -3,7 +3,7 @@
 mod sealed;
 
 pub use num_traits::{
-    WrappingAdd, WrappingMul, WrappingNeg, WrappingShl, WrappingShr, WrappingSub,
+    ConstZero, WrappingAdd, WrappingMul, WrappingNeg, WrappingShl, WrappingShr, WrappingSub,
 };
 
 pub(crate) use sealed::PrecomputeInverterWithAdjuster;
@@ -264,15 +264,7 @@ pub trait Zero: ConstantTimeEq + Sized {
     }
 }
 
-/// Trait for associating a constant representing zero.
-///
-/// Types which impl this trait automatically receive a blanket impl of [`Zero`].
-pub trait ConstZero: Zero {
-    /// The value `0`.
-    const ZERO: Self;
-}
-
-impl<T: ConstZero> Zero for T {
+impl<T: ConstZero + ConstantTimeEq> Zero for T {
     #[inline(always)]
     fn zero() -> T {
         Self::ZERO