From a168f49b667050bdee65202d73dd05c81036107d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johel=20Ernesto=20Guerrero=20Pe=C3=B1a?=
 <johelegp@gmail.com>
Date: Sat, 6 Feb 2021 21:42:25 -0400
Subject: [PATCH] fix: lack of compound assignment from dimensionless<one>

---
 src/include/units/quantity.h            | 14 ++++++++++++++
 test/unit_test/static/quantity_test.cpp |  8 ++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/include/units/quantity.h b/src/include/units/quantity.h
index 8911cc73..574318a7 100644
--- a/src/include/units/quantity.h
+++ b/src/include/units/quantity.h
@@ -210,6 +210,13 @@ public:
     value_ *= rhs;
     return *this;
   }
+  template<typename Rep2>
+  constexpr quantity& operator*=(const dimensionless<units::one, Rep2>& rhs)
+    requires requires(rep a, const Rep2 b) { { a *= b } -> std::same_as<rep&>; }
+  {
+    value_ *= rhs.count();
+    return *this;
+  }
 
   template<typename Rep2>
   constexpr quantity& operator/=(const Rep2& rhs)
@@ -218,6 +225,13 @@ public:
     value_ /= rhs;
     return *this;
   }
+  template<typename Rep2>
+  constexpr quantity& operator/=(const dimensionless<units::one, Rep2>& rhs)
+    requires requires(rep a, const Rep2 b) { { a /= b } -> std::same_as<rep&>; }
+  {
+    value_ /= rhs.count();
+    return *this;
+  }
 
   constexpr quantity& operator%=(const rep& rhs)
     requires (!floating_point_<rep>) &&
diff --git a/test/unit_test/static/quantity_test.cpp b/test/unit_test/static/quantity_test.cpp
index be52bc9a..81512094 100644
--- a/test/unit_test/static/quantity_test.cpp
+++ b/test/unit_test/static/quantity_test.cpp
@@ -275,6 +275,8 @@ static_assert((1_q_m += 1_q_m).count() == 2);
 static_assert((2_q_m -= 1_q_m).count() == 1);
 static_assert((1_q_m *= 2).count() == 2);
 static_assert((2_q_m /= 2).count() == 1);
+static_assert((1_q_m *= quantity(2)).count() == 2);
+static_assert((2_q_m /= quantity(2)).count() == 1);
 static_assert((7_q_m %= 2).count() == 1);
 static_assert((7_q_m %= 2_q_m).count() == 1);
 
@@ -285,6 +287,8 @@ static_assert((5.5_q_m -= 3_q_m).count() == 2.5);
 static_assert((1123_q_m -= 1_q_km).count() == 123);
 static_assert((2.5_q_m *= 3).count() == 7.5);
 static_assert((7.5_q_m /= 3).count() == 2.5);
+static_assert((2.5_q_m *= quantity(3)).count() == 7.5);
+static_assert((7.5_q_m /= quantity(3)).count() == 2.5);
 static_assert((3500_q_m %= 1_q_km).count() == 500);
 
 #ifndef COMP_MSVC  // TODO ICE (https://developercommunity2.visualstudio.com/t/ICE-on-a-constexpr-operator-in-mp-unit/1302907)
@@ -292,6 +296,8 @@ static_assert((3500_q_m %= 1_q_km).count() == 500);
 // (warning disabled in CMake for this file)
 static_assert((22_q_m *= 33.33).count() == 733);
 static_assert((22_q_m /= 3.33).count() == 6);
+static_assert((22_q_m *= quantity(33.33)).count() == 733);
+static_assert((22_q_m /= quantity(3.33)).count() == 6);
 #endif
 
 template<typename Metre>
@@ -512,6 +518,8 @@ static_assert((10_q_s * 2_q_kHz).count() == 20);
 
 // dimensionless
 
+static_assert((quantity{3} *= quantity{2}) == 6);
+static_assert((quantity{6} /= quantity{2}) == 3);
 static_assert(quantity{1} + quantity{1} == 2);
 static_assert(1 + quantity{1} == 2);
 static_assert(quantity{1} + 1 == 2);