From 0653fc44bb5d9d2df740d68b940956cf8cdec5d2 Mon Sep 17 00:00:00 2001
From: AsukaMinato <i@asukaminato.eu.org>
Date: Wed, 22 Nov 2023 15:04:52 +0900
Subject: [PATCH] fix

---
 src/optimal_retention.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/optimal_retention.rs b/src/optimal_retention.rs
index fdaf0fcf..9926c020 100644
--- a/src/optimal_retention.rs
+++ b/src/optimal_retention.rs
@@ -551,7 +551,7 @@ impl<B: Backend> FSRS<B> {
             }
             // update by at least tol1
             u = x + if rat.abs() < tol1 {
-                rat.is_sign_positive() as i8 as f64 * tol1
+                tol1 * if rat >= 0.0 { 1.0 } else { -1.0 }
             } else {
                 rat
             };