From 1096d8d8bafd6410bdb42ea7704f40b5d505e9ab Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Thu, 1 Sep 2022 12:18:18 +0200
Subject: [PATCH] fix: luminous flux support fixed

---
 .../include/units/isq/dimensions/luminous_flux.h    | 10 +++++++---
 src/systems/si/include/units/isq/si/luminous_flux.h | 13 +++++++------
 test/unit_test/static/si_test.cpp                   |  3 +--
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/systems/isq/include/units/isq/dimensions/luminous_flux.h b/src/systems/isq/include/units/isq/dimensions/luminous_flux.h
index a86a6285..ffa81053 100644
--- a/src/systems/isq/include/units/isq/dimensions/luminous_flux.h
+++ b/src/systems/isq/include/units/isq/dimensions/luminous_flux.h
@@ -23,12 +23,16 @@
 #pragma once
 
 #include <units/concepts.h>
-#include <units/isq/dimensions/power.h>
+#include <units/generic/solid_angle.h>
+#include <units/isq/dimensions/luminous_intensity.h>
 
 namespace units::isq {
 
-template<typename Child, Unit U, typename... Dims>
-using dim_luminous_flux = dim_power<Child, U, Dims...>;
+template<typename Child, Unit U, typename...>
+struct dim_luminous_flux;
+
+template<typename Child, Unit U, DimensionOfT<dim_luminous_intensity> I, DimensionOfT<dim_solid_angle> A>
+struct dim_luminous_flux<Child, U, I, A> : derived_dimension<Child, U, exponent<I, 1>, exponent<A, 1>> {};
 
 template<typename T>
 concept LuminousFlux = QuantityOfT<T, dim_luminous_flux>;
diff --git a/src/systems/si/include/units/isq/si/luminous_flux.h b/src/systems/si/include/units/isq/si/luminous_flux.h
index a1de8d48..c35f5e8c 100644
--- a/src/systems/si/include/units/isq/si/luminous_flux.h
+++ b/src/systems/si/include/units/isq/si/luminous_flux.h
@@ -23,25 +23,26 @@
 #pragma once
 
 // IWYU pragma: begin_exports
-#include <units/isq/si/power.h>
+#include <units/isq/dimensions/luminous_flux.h>
+#include <units/isq/si/luminous_intensity.h>
 #include <units/quantity.h>
 #include <units/reference.h>
 #include <units/symbol_text.h>
 // IWYU pragma: end_exports
 
+#include <units/generic/solid_angle.h>
 #include <units/isq/si/prefixes.h>
 #include <units/unit.h>
 
 namespace units::isq::si {
 
-// TODO Is this correct? Should we account for steradian here? How?
+struct lumen : named_unit<lumen, "lm"> {};
 
-struct lumen : named_scaled_unit<lumen, "lm", mag<ratio(1, 683)>(), watt> {};
-
-using dim_luminous_flux = dim_power;
+struct dim_luminous_flux :
+    isq::dim_luminous_flux<dim_luminous_flux, lumen, dim_luminous_intensity, dim_solid_angle<>> {};
 
 template<UnitOf<dim_luminous_flux> U, Representation Rep = double>
-using luminous_flux = power<U, Rep>;
+using luminous_flux = quantity<dim_luminous_flux, U, Rep>;
 
 #ifndef UNITS_NO_LITERALS
 
diff --git a/test/unit_test/static/si_test.cpp b/test/unit_test/static/si_test.cpp
index 2299a0f5..b10b987b 100644
--- a/test/unit_test/static/si_test.cpp
+++ b/test/unit_test/static/si_test.cpp
@@ -241,8 +241,7 @@ static_assert(kilogray::symbol == "kGy");
 
 // luminous flux
 
-static_assert(683_q_lm == 1_q_W);
-
+static_assert(1_q_sr * 1_q_cd == 1_q_lm);
 static_assert(lumen::symbol == "lm");
 
 /* ************** DERIVED DIMENSIONS IN TERMS OF BASE UNITS **************** */