From 9461cd84f2419a3e645412156f3bf0f01d21542f Mon Sep 17 00:00:00 2001
From: Clar Charr <clar@charr.xyz>
Date: Mon, 19 Feb 2018 15:05:11 -0500
Subject: [PATCH] Add is_one.

---
 src/identities.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/identities.rs b/src/identities.rs
index 14f5ac0..0158a46 100644
--- a/src/identities.rs
+++ b/src/identities.rs
@@ -79,6 +79,14 @@ pub trait One: Sized + Mul<Self, Output = Self> {
     /// `static mut`s.
     // FIXME (#5527): This should be an associated constant
     fn one() -> Self;
+
+    /// Returns `true` if `self` is equal to the multiplicative identity.
+    ///
+    /// Compatibility note: this method will be a requirement to implement in the future; new
+    /// implementors should provide it for future-compatibility.
+    fn is_one(&self) -> bool where Self: PartialEq {
+        *self == Self::one()
+    }
 }
 
 macro_rules! one_impl {