Inv implementation for Decimal (#495)

Fixes #494 Co-authored-by: Manuel Bärenz <m.baerenz@sonnen.de>
paupino · Mar 17, 2022 · 4b97ec4 · 4b97ec4
1 parent 2d43258
commit 4b97ec4
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Showing 2 changed files with 19 additions and 5 deletions.
diff --git a/src/arithmetic_impls.rs b/src/arithmetic_impls.rs
@@ -3,7 +3,7 @@
 
 use crate::{decimal::CalculationResult, ops, Decimal};
 use core::ops::{Add, Div, Mul, Rem, Sub};
-use num_traits::{CheckedAdd, CheckedDiv, CheckedMul, CheckedRem, CheckedSub};
+use num_traits::{CheckedAdd, CheckedDiv, CheckedMul, CheckedRem, CheckedSub, Inv};
 
 // Macros and `Decimal` implementations
 
@@ -32,10 +32,10 @@ macro_rules! impl_checked {
 macro_rules! impl_saturating {
     ($long:literal, $short:literal, $fun:ident, $impl:ident, $cmp:ident) => {
         #[doc = concat!(
-            "Saturating ", 
-            $long, 
+            "Saturating ",
+            $long,
             ". Computes `self ",
-            $short, 
+            $short,
             " other`, saturating at the relevant upper or lower boundary.",
         )]
         #[inline(always)]
@@ -198,6 +198,15 @@ impl CheckedRem for Decimal {
     }
 }
 
+impl Inv for Decimal {
+    type Output = Self;
+
+    #[inline]
+    fn inv(self) -> Self {
+        Decimal::ONE / self
+    }
+}
+
 forward_all_binop!(impl Div for Decimal, div);
 impl<'a, 'b> Div<&'b Decimal> for &'a Decimal {
     type Output = Decimal;

diff --git a/tests/decimal_tests.rs b/tests/decimal_tests.rs
@@ -5,7 +5,7 @@ use core::{
     convert::{TryFrom, TryInto},
     str::FromStr,
 };
-use num_traits::{Signed, ToPrimitive};
+use num_traits::{Inv, Signed, ToPrimitive};
 use rust_decimal::{Decimal, Error, RoundingStrategy};
 
 #[test]
@@ -3366,6 +3366,11 @@ fn test_constants() {
     assert_eq!("2", Decimal::TWO.to_string());
 }
 
+#[test]
+fn test_inv() {
+    assert_eq!("0.01", Decimal::ONE_HUNDRED.inv().to_string());
+}
+
 // Mathematical features
 #[cfg(feature = "maths")]
 mod maths {