Merge pull request #167 from Ten0/less_implicit_panic_on_binary_operations

Remove implicit panics in NotNan<T> x T operators

Author: mbrubeck

src/lib.rs

@@ -1227,10 +1227,7 @@ impl<T: FloatCore + Num> Num for OrderedFloat<T> {
 /// ```
 /// use ordered_float::NotNan;
 ///
-/// let mut v = [
-///     NotNan::new(2.0).unwrap(),
-///     NotNan::new(1.0).unwrap(),
-/// ];
+/// let mut v = [NotNan::new(2.0).unwrap(), NotNan::new(1.0).unwrap()];
 /// v.sort();
 /// assert_eq!(v, [1.0, 2.0]);
 /// ```
@@ -1270,7 +1267,6 @@ impl<T: FloatCore + Num> Num for OrderedFloat<T> {
 /// [transmute](core::mem::transmute) or pointer casts to convert between any type `T` and
 /// `NotNan<T>`, as long as this does not create a NaN value.
 /// However, consider using [`bytemuck`] as a safe alternative if possible.
-///
 #[cfg_attr(
     not(feature = "bytemuck"),
     doc = "[`bytemuck`]: https://docs.rs/bytemuck/1/"
@@ -1384,9 +1380,10 @@ impl NotNan<f64> {
     /// Note: For the reverse conversion (from `NotNan<f32>` to `NotNan<f64>`), you can use
     /// `.into()`.
     pub fn as_f32(self) -> NotNan<f32> {
-        // This is not destroying invariants, as it is a pure rounding operation. The only two special
-        // cases are where f32 would be overflowing, then the operation yields Infinity, or where
-        // the input is already NaN, in which case the invariant is already broken elsewhere.
+        // This is not destroying invariants, as it is a pure rounding operation. The only two
+        // special cases are where f32 would be overflowing, then the operation yields
+        // Infinity, or where the input is already NaN, in which case the invariant is
+        // already broken elsewhere.
         NotNan(self.0 as f32)
     }
 }
@@ -1472,13 +1469,13 @@ impl<T: FloatCore> PartialEq<T> for NotNan<T> {
 
 /// Adds a float directly.
 ///
-/// Panics if the provided value is NaN or the computation results in NaN
+/// This returns a `T` and not a `NotNan<T>` because if the added value is NaN, this will be NaN
 impl<T: FloatCore> Add<T> for NotNan<T> {
-    type Output = Self;
+    type Output = T;
 
     #[inline]
-    fn add(self, other: T) -> Self {
-        NotNan::new(self.0 + other).expect("Addition resulted in NaN")
+    fn add(self, other: T) -> Self::Output {
+        self.0 + other
     }
 }
 
@@ -1500,25 +1497,27 @@ impl<'a, T: FloatCore + Sum + 'a> Sum<&'a NotNan<T>> for NotNan<T> {
 
 /// Subtracts a float directly.
 ///
-/// Panics if the provided value is NaN or the computation results in NaN
+/// This returns a `T` and not a `NotNan<T>` because if the substracted value is NaN, this will be
+/// NaN
 impl<T: FloatCore> Sub<T> for NotNan<T> {
-    type Output = Self;
+    type Output = T;
 
     #[inline]
-    fn sub(self, other: T) -> Self {
-        NotNan::new(self.0 - other).expect("Subtraction resulted in NaN")
+    fn sub(self, other: T) -> Self::Output {
+        self.0 - other
     }
 }
 
 /// Multiplies a float directly.
 ///
-/// Panics if the provided value is NaN or the computation results in NaN
+/// This returns a `T` and not a `NotNan<T>` because if the multiplied value is NaN, this will be
+/// NaN
 impl<T: FloatCore> Mul<T> for NotNan<T> {
-    type Output = Self;
+    type Output = T;
 
     #[inline]
-    fn mul(self, other: T) -> Self {
-        NotNan::new(self.0 * other).expect("Multiplication resulted in NaN")
+    fn mul(self, other: T) -> Self::Output {
+        self.0 * other
     }
 }
 
@@ -1537,25 +1536,26 @@ impl<'a, T: FloatCore + Product + 'a> Product<&'a NotNan<T>> for NotNan<T> {
 
 /// Divides a float directly.
 ///
-/// Panics if the provided value is NaN or the computation results in NaN
+/// This returns a `T` and not a `NotNan<T>` because if the divided-by value is NaN, this will be
+/// NaN
 impl<T: FloatCore> Div<T> for NotNan<T> {
-    type Output = Self;
+    type Output = T;
 
     #[inline]
-    fn div(self, other: T) -> Self {
-        NotNan::new(self.0 / other).expect("Division resulted in NaN")
+    fn div(self, other: T) -> Self::Output {
+        self.0 / other
     }
 }
 
 /// Calculates `%` with a float directly.
 ///
-/// Panics if the provided value is NaN or the computation results in NaN
+/// This returns a `T` and not a `NotNan<T>` because if the RHS is NaN, this will be NaN
 impl<T: FloatCore> Rem<T> for NotNan<T> {
-    type Output = Self;
+    type Output = T;
 
     #[inline]
-    fn rem(self, other: T) -> Self {
-        NotNan::new(self.0 % other).expect("Rem resulted in NaN")
+    fn rem(self, other: T) -> Self::Output {
+        self.0 % other
     }
 }
 
@@ -1566,12 +1566,13 @@ macro_rules! impl_not_nan_binop {
 
             #[inline]
             fn $method(self, other: Self) -> Self {
-                self.$method(other.0)
+                NotNan::new(self.0.$method(other.0))
+                    .expect("Operation on two NotNan resulted in NaN")
             }
         }
 
         impl<T: FloatCore> $imp<&T> for NotNan<T> {
-            type Output = NotNan<T>;
+            type Output = T;
 
             #[inline]
             fn $method(self, other: &T) -> Self::Output {
@@ -1584,7 +1585,7 @@ macro_rules! impl_not_nan_binop {
 
             #[inline]
             fn $method(self, other: &Self) -> Self::Output {
-                self.$method(other.0)
+                self.$method(*other)
             }
         }
 
@@ -1593,7 +1594,7 @@ macro_rules! impl_not_nan_binop {
 
             #[inline]
             fn $method(self, other: Self) -> Self::Output {
-                (*self).$method(other.0)
+                (*self).$method(*other)
             }
         }
 
@@ -1602,12 +1603,12 @@ macro_rules! impl_not_nan_binop {
 
             #[inline]
             fn $method(self, other: NotNan<T>) -> Self::Output {
-                (*self).$method(other.0)
+                (*self).$method(other)
             }
         }
 
         impl<T: FloatCore> $imp<T> for &NotNan<T> {
-            type Output = NotNan<T>;
+            type Output = T;
 
             #[inline]
             fn $method(self, other: T) -> Self::Output {
@@ -1616,39 +1617,25 @@ macro_rules! impl_not_nan_binop {
         }
 
         impl<T: FloatCore> $imp<&T> for &NotNan<T> {
-            type Output = NotNan<T>;
+            type Output = T;
 
             #[inline]
             fn $method(self, other: &T) -> Self::Output {
                 (*self).$method(*other)
             }
         }
 
-        impl<T: FloatCore + $assign_imp> $assign_imp<T> for NotNan<T> {
-            #[inline]
-            fn $assign_method(&mut self, other: T) {
-                *self = (*self).$method(other);
-            }
-        }
-
-        impl<T: FloatCore + $assign_imp> $assign_imp<&T> for NotNan<T> {
-            #[inline]
-            fn $assign_method(&mut self, other: &T) {
-                *self = (*self).$method(*other);
-            }
-        }
-
         impl<T: FloatCore + $assign_imp> $assign_imp for NotNan<T> {
             #[inline]
             fn $assign_method(&mut self, other: Self) {
-                (*self).$assign_method(other.0);
+                *self = (*self).$method(other);
             }
         }
 
         impl<T: FloatCore + $assign_imp> $assign_imp<&Self> for NotNan<T> {
             #[inline]
             fn $assign_method(&mut self, other: &Self) {
-                (*self).$assign_method(other.0);
+                *self = (*self).$method(*other);
             }
         }
     };