From cc25f9b0de9843389380d31b66dbdbc99b30fb97 Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Mon, 4 Nov 2024 19:13:48 +0100
Subject: [PATCH] refactor: `get_complexity` refactored to returned maximum
 complexity of an element (instead of the sum of elements)

---
 src/core/include/mp-units/framework/quantity_spec.h |  7 +++++--
 test/static/quantity_spec_test.cpp                  | 12 +++++++++---
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/core/include/mp-units/framework/quantity_spec.h b/src/core/include/mp-units/framework/quantity_spec.h
index 6a7cb9be..802cece1 100644
--- a/src/core/include/mp-units/framework/quantity_spec.h
+++ b/src/core/include/mp-units/framework/quantity_spec.h
@@ -610,7 +610,10 @@ template<QuantitySpec Q>
 template<typename... Ts>
 [[nodiscard]] consteval int get_complexity(type_list<Ts...>)
 {
-  return (0 + ... + get_complexity(Ts{}));
+  if constexpr (sizeof...(Ts) == 0)
+    return 0;
+  else
+    return max({get_complexity(Ts{})...});
 }
 
 template<QuantitySpec Q, int... Ints>
@@ -629,7 +632,7 @@ template<QuantitySpec Q>
 [[nodiscard]] consteval int get_complexity(Q)
 {
   if constexpr (DerivedQuantitySpec<Q>)
-    return get_complexity(typename Q::_num_{}) + get_complexity(typename Q::_den_{});
+    return max(get_complexity(typename Q::_num_{}), get_complexity(typename Q::_den_{}));
   else if constexpr (requires { Q::_equation_; })
     return 1 + get_complexity(Q::_equation_);
   else
diff --git a/test/static/quantity_spec_test.cpp b/test/static/quantity_spec_test.cpp
index 63bb95bb..73778da6 100644
--- a/test/static/quantity_spec_test.cpp
+++ b/test/static/quantity_spec_test.cpp
@@ -458,9 +458,15 @@ static_assert(get_complexity(force) == 3);
 
 static_assert(get_complexity(acceleration * time) == 2);
 static_assert(get_complexity(acceleration / time) == 2);
-static_assert(get_complexity(speed * area) == 2);
-static_assert(get_complexity(speed / frequency) == 2);
-static_assert(get_complexity(speed * area / frequency) == 3);
+static_assert(get_complexity(speed * area) == 1);
+static_assert(get_complexity(acceleration * area) == 2);
+static_assert(get_complexity(acceleration * force) == 3);
+static_assert(get_complexity(speed / frequency) == 1);
+static_assert(get_complexity(acceleration / frequency) == 2);
+static_assert(get_complexity(force / frequency) == 3);
+static_assert(get_complexity(area / acceleration) == 2);
+static_assert(get_complexity(area / force) == 3);
+static_assert(get_complexity(speed * area / frequency) == 1);
 
 // explode
 static_assert(explode<get_complexity(inverse(time))>(frequency).quantity == inverse(period_duration));