add div_euclid and rem_euclid

README.md

@@ -72,12 +72,16 @@ The conversions supported cover the following cases.
 
   * [`Rem`] and [`RemAssign`] were implemented for fixed-point
     numbers.
-  * The method [`checked_rem`] was added to all fixed-point types and
+  * The following methods were added to all fixed-point types and to
-    to the [`Fixed`] trait.
+    the [`Fixed`] trait:
+	  *  [`checked_rem`]
+	  *  [`div_euclid`], [`rem_euclid`]
 
-[`checked_rem`]: https://docs.rs/fixed/0.5.3/fixed/struct.FixedI32.html#method.checked_rem
-[`Rem`]: https://doc.rust-lang.org/nightly/core/ops/trait.Rem.html
 [`RemAssign`]: https://doc.rust-lang.org/nightly/core/ops/trait.RemAssign.html
+[`Rem`]: https://doc.rust-lang.org/nightly/core/ops/trait.Rem.html
+[`checked_rem`]: https://docs.rs/fixed/0.5.3/fixed/struct.FixedI32.html#method.checked_rem
+[`div_euclid`]: https://docs.rs/fixed/0.5.3/fixed/struct.FixedI32.html#method.div_euclid
+[`rem_euclid`]: https://docs.rs/fixed/0.5.3/fixed/struct.FixedI32.html#method.rem_euclid
 
 ### Version 0.5.2 news (2020-02-02)
 

RELEASES.md

@@ -9,8 +9,10 @@ Version 0.5.3 (unreleased)
 ==========================
 
   * `Rem` and `RemAssign` were implemented for fixed-point numbers.
-  * The method `checked_rem` was added to all fixed-point types and to
+  * The following methods were added to all fixed-point types and to
-    the `Fixed` trait.
+    the `Fixed` trait:
+	  * `checked_rem`
+	  * `div_euclid`, `rem_euclid`x
 
 Version 0.5.2 (2020-02-02)
 ==========================

src/macros_frac.rs

@@ -137,6 +137,83 @@ assert_eq!(Fix::from_num(-5).signum(), -1);
                 }
             }
 
+            comment! {
+                "Euclidean division.
+
+# Panics
+
+Panics if the divisor is zero",
+                if_signed_else_empty_str! {
+                    $Signedness,
+                    " or if the division results in overflow",
+                },
+                ".
+
+# Examples
+
+```rust
+use fixed::{types::extra::U4, ", $s_fixed, "};
+type Fix = ", $s_fixed, "<U4>;
+assert_eq!(Fix::from_num(7.5).div_euclid(Fix::from_num(2)), Fix::from_num(3));
+",
+                if_signed_else_empty_str! {
+                    $Signedness,
+                    "assert_eq!(Fix::from_num(-7.5).div_euclid(Fix::from_num(2)), Fix::from_num(-4));
+",
+                },
+                "```
+";
+                #[inline]
+                pub fn div_euclid(self, rhs: $Fixed<Frac>) -> $Fixed<Frac> {
+                    let q = (self / rhs).round_to_zero();
+                    if_signed! {
+                        $Signedness;
+                        if (self % rhs).is_negative() {
+                            return if rhs.is_positive() {
+                                q - Self::from_num(1)
+                            } else {
+                                q + Self::from_num(1)
+                            };
+                        }
+                    }
+                    q
+                }
+            }
+
+            comment! {
+                "Remainder for Euclidean division.
+
+# Panics
+
+Panics if the divisor is zero.
+
+# Examples
+
+```rust
+use fixed::{types::extra::U4, ", $s_fixed, "};
+type Fix = ", $s_fixed, "<U4>;
+assert_eq!(Fix::from_num(7.5).rem_euclid(Fix::from_num(2)), Fix::from_num(1.5));
+",
+                if_signed_else_empty_str! {
+                    $Signedness,
+                    "assert_eq!(Fix::from_num(-7.5).rem_euclid(Fix::from_num(2)), Fix::from_num(0.5));
+",
+                },
+                "```
+";
+                #[inline]
+                pub fn rem_euclid(self, rhs: $Fixed<Frac>) -> $Fixed<Frac> {
+                    let r = self % rhs;
+                    if_signed! {
+                        $Signedness;
+                        if r.is_negative() {
+                            return r + rhs.abs();
+                        }
+                    }
+                    r
+                }
+            }
+
             comment! {
                 "Checked multiplication. Returns the product, or [`None`] on overflow.
 

src/traits.rs

@@ -590,6 +590,20 @@ where
     /// Shifts to the right by `n` bits, wrapping the truncated bits to the left end.
     fn rotate_right(self, n: u32) -> Self;
 
+    /// Euclidean division by an integer.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the divisor is zero or if the division results in overflow.
+    fn div_euclid(self, rhs: Self) -> Self;
+
+    /// Remainder for Euclidean division.
+    ///
+    /// # Panics
+    ///
+    /// Panics if the divisor is zero.
+    fn rem_euclid(self, rhs: Self) -> Self;
+
     /// Euclidean division by an integer.
     ///
     /// # Panics
@@ -1525,6 +1539,8 @@ macro_rules! impl_fixed {
             trait_delegate! { fn trailing_zeros(self) -> u32 }
             trait_delegate! { fn rotate_left(self, n: u32) -> Self }
             trait_delegate! { fn rotate_right(self, n: u32) -> Self }
+            trait_delegate! { fn div_euclid(self, rhs: Self) -> Self }
+            trait_delegate! { fn rem_euclid(self, rhs: Self) -> Self }
             trait_delegate! { fn div_euclid_int(self, rhs: Self::Bits) -> Self }
             trait_delegate! { fn rem_euclid_int(self, rhs: Self::Bits) -> Self }
             trait_delegate! { fn checked_neg(self) -> Option<Self> }