From c754fa9e4ce5c26e1b04d0b377602f2432132b0d Mon Sep 17 00:00:00 2001
From: Mike Boutin <mike.boutin@gmail.com>
Date: Sun, 26 Nov 2017 09:04:36 -0500
Subject: [PATCH] Explicitly implement `{Mul,Div}<Quantity> for V`.

Explicit implementations allow for a literal left hand side. Part of #29.
---
 src/si/frequency.rs |  8 +++----
 src/system.rs       | 55 ++++++++++++++++++++++++++++-----------------
 src/tests.rs        |  2 +-
 3 files changed, 39 insertions(+), 26 deletions(-)

diff --git a/src/si/frequency.rs b/src/si/frequency.rs
index 32c1a4de..a930c479 100644
--- a/src/si/frequency.rs
+++ b/src/si/frequency.rs
@@ -50,8 +50,8 @@ mod tests {
 
         #[test]
         fn check_dimension() {
-            let _: Time<V> = Frequency::new::<f::hertz>(V::one()).recip();
-            let _: Frequency<V> = Time::new::<t::second>(V::one()).recip();
+            let _: Time<V> = V::one() / Frequency::new::<f::hertz>(V::one());
+            let _: Frequency<V> = V::one() / Time::new::<t::second>(V::one());
         }
 
         #[test]
@@ -80,10 +80,10 @@ mod tests {
 
             // TODO #17 Convert to == once PartialEq is implemented.
             fn test<T: t::Conversion<V>, F: f::Conversion<V>>(t: T, f: F) {
-                assert_ulps_eq!((Time::new::<T>(V::one()).recip()).get(f),
+                assert_ulps_eq!((V::one() / Time::new::<T>(V::one())).get(f),
                     Frequency::new::<F>(V::one()).get(f), epsilon = V::epsilon());
                 assert_ulps_eq!(Time::new::<T>(V::one()).get(t),
-                    (Frequency::new::<F>(V::one()).recip()).get(t), epsilon = V::epsilon());
+                    (V::one() / Frequency::new::<F>(V::one())).get(t), epsilon = V::epsilon());
             }
         }
     }
diff --git a/src/system.rs b/src/system.rs
index 16de1fae..c9a68499 100644
--- a/src/system.rs
+++ b/src/system.rs
@@ -344,7 +344,8 @@ macro_rules! system {
                 $AddSubAssignTrait:ident, $addsubassign_fun:ident, $addsubassign_op:tt,
                 $AddSubAlias:ident,
                 $MulDivTrait:ident, $muldiv_fun:ident, $muldiv_op:tt,
-                $MulDivAssignTrait:ident, $muldivassign_fun:ident, $muldivassign_op:tt
+                $MulDivAssignTrait:ident, $muldivassign_fun:ident, $muldivassign_op:tt,
+                $Mod:ident
             ) => {
                 impl<D, Ul, Ur, V> $crate::stdlib::ops::$AddSubTrait<Quantity<D, Ur, V>>
                     for Quantity<D, Ul, V>
@@ -425,24 +426,6 @@ macro_rules! system {
                     }
                 }
 
-                // impl<D, U, V> $crate::stdlib::ops::$MulDivTrait<Quantity<D, U, V>> for V
-                // where
-                //     D: Dimension + ?Sized,
-                //     U: Units<V> + ?Sized,
-                //     V: $crate::num::Num + $crate::stdlib::ops::$MulDivTrait<V>,
-                // {
-                //     type Output = Quantity<D, U, V>;
-
-                //     #[inline(always)]
-                //     fn $muldiv_fun(self, rhs: Quantity<D, U, V>) -> Self::Output {
-                //         Quantity {
-                //             dimension: $crate::stdlib::marker::PhantomData,
-                //             units: $crate::stdlib::marker::PhantomData,
-                //             value: self $muldiv_op rhs.value,
-                //         }
-                //     }
-                // }
-
                 impl<D, U, V> $crate::stdlib::ops::$MulDivAssignTrait<V> for Quantity<D, U, V>
                 where
                     D: Dimension + ?Sized,
@@ -455,13 +438,43 @@ macro_rules! system {
                         self.value $muldivassign_op rhs;
                     }
                 }
+
+                #[doc(hidden)]
+                mod $Mod {
+                    storage_types! {
+                        use super::super::*;
+
+                        impl<D, U> $crate::stdlib::ops::$MulDivTrait<Quantity<D, U, V>> for V
+                        where
+                            D: Dimension + ?Sized,
+                            U: Units<V> + ?Sized,
+                            $($crate::typenum::Z0: $crate::stdlib::ops::$AddSubTrait<D::$symbol>,)+
+                        {
+                            type Output = Quantity<
+                                $quantities<
+                                    $($crate::typenum::$AddSubAlias<
+                                      $crate::typenum::Z0,
+                                      D::$symbol>,)+>,
+                                U, V>;
+
+                            #[inline(always)]
+                            fn $muldiv_fun(self, rhs: Quantity<D, U, V>) -> Self::Output {
+                                Quantity {
+                                    dimension: $crate::stdlib::marker::PhantomData,
+                                    units: $crate::stdlib::marker::PhantomData,
+                                    value: self $muldiv_op rhs.value,
+                                }
+                            }
+                        }
+                    }
+                }
             };
         }
 
         impl_ops!(Add, add, +, AddAssign, add_assign, +=, Sum,
-            Mul, mul, *, MulAssign, mul_assign, *=);
+            Mul, mul, *, MulAssign, mul_assign, *=, add_mul);
         impl_ops!(Sub, sub, -, SubAssign, sub_assign, -=, Diff,
-            Div, div, /, DivAssign, div_assign, /=);
+            Div, div, /, DivAssign, div_assign, /=, sub_div);
 
         impl<D, U, V> Quantity<D, U, V>
         where
diff --git a/src/tests.rs b/src/tests.rs
index 26bdf67c..95db3328 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -245,7 +245,7 @@ storage_types! {
                 format!("{:?}", TLength::new::<meter>(V::one())));
             assert_eq!(
                 format!("{:?} m^-1", V::one()),
-                format!("{:?}", TLength::new::<meter>(V::one()).recip()));
+                format!("{:?}", V::one() / TLength::new::<meter>(V::one())));
             assert_eq!(
                 format!("{:.2?} m^1", V::one()),
                 format!("{:.2?}", TLength::new::<meter>(V::one())));