From 577f0332f2744ee4dc0c4f2d5ca1a43c74d9d62e Mon Sep 17 00:00:00 2001
From: Shaopeng Wang <spxwang@gmail.com>
Date: Wed, 11 Mar 2020 15:26:17 +1300
Subject: [PATCH] Impl saturating_abs for Fixed128. (#116)
---
utilities/src/fixed_128.rs | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/utilities/src/fixed_128.rs b/utilities/src/fixed_128.rs
index 8623622..601d5da 100644
--- a/utilities/src/fixed_128.rs
+++ b/utilities/src/fixed_128.rs
@@ -172,6 +172,19 @@ impl Fixed128 {
pub fn is_zero(&self) -> bool {
self.0 == 0
}
+
+ /// Saturating absolute value. Returning MAX if `parts` == i128::MIN instead of overflowing.
+ pub fn saturating_abs(&self) -> Self {
+ if self.0 == i128::min_value() {
+ return Fixed128::max_value();
+ }
+
+ if self.0.is_negative() {
+ Fixed128::from_parts(self.0 * -1)
+ } else {
+ *self
+ }
+ }
}
impl Saturating for Fixed128 {
@@ -530,4 +543,14 @@ mod tests {
let deserialized: Fixed128 = serde_json::from_str(&serialized).unwrap();
assert_eq!(deserialized, minus_two_point_five);
}
+
+ #[test]
+ fn saturating_abs_should_work() {
+ // normal
+ assert_eq!(Fixed128::from_parts(1).saturating_abs(), Fixed128::from_parts(1));
+ assert_eq!(Fixed128::from_parts(-1).saturating_abs(), Fixed128::from_parts(1));
+
+ // saturating
+ assert_eq!(Fixed128::min_value().saturating_abs(), Fixed128::max_value());
+ }
}
--
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