From 5fd8269dcc1371129affa06120b9416785785c02 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Wed, 24 Apr 2024 11:35:10 -0400
Subject: [PATCH] xo-unit: + Dimensionless/Quantity

---
 include/xo/unit/Quantity.hpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/xo/unit/Quantity.hpp b/include/xo/unit/Quantity.hpp
index 604664b2..8f02c32f 100644
--- a/include/xo/unit/Quantity.hpp
+++ b/include/xo/unit/Quantity.hpp
@@ -242,8 +242,7 @@ namespace xo {
             return Quantity::divide(x, y);
         }
 
-        /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
-         **/
+        /** note: doesn not require unit scaling, so constexpr with c++23 **/
         template <typename Quantity, typename Dimensionless>
         requires quantity2_concept<Quantity> && std::is_arithmetic_v<Dimensionless>
         constexpr auto
@@ -252,6 +251,15 @@ namespace xo {
             return x.divide_by(y);
         }
 
+        /** note: doesn not require unit scaling, so constexpr with c++23 **/
+        template <typename Dimensionless, typename Quantity>
+        requires std::is_arithmetic_v<Dimensionless> && quantity2_concept<Quantity>
+        constexpr auto
+        operator/ (Dimensionless x, const Quantity & y)
+        {
+            return y.divide_into(x);
+        }
+
         /** note: won't have constexpr result until c++26 (when ::sqrt(), ::pow() are constexpr)
          **/
         template <typename Quantity, typename Quantity2>