From 458ac0918bee54ec81475c725d39ac5c34d421b2 Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Tue, 8 Oct 2019 21:20:37 +0200
Subject: [PATCH] Scalar constraint added to quantity constructor

---
 src/include/units/quantity.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/include/units/quantity.h b/src/include/units/quantity.h
index 7cd558ad..b1c1c17a 100644
--- a/src/include/units/quantity.h
+++ b/src/include/units/quantity.h
@@ -191,8 +191,9 @@ namespace units {
     quantity() = default;
     quantity(const quantity&) = default;
 
-    template<std::convertible_to<rep> Rep2>
-        requires treat_as_floating_point<rep> || (!treat_as_floating_point<Rep2>)
+    template<Scalar Rep2>
+        requires std::convertible_to<Rep2, rep> &&
+                 (treat_as_floating_point<rep> || (!treat_as_floating_point<Rep2>))
     constexpr explicit quantity(const Rep2& r) : value_{static_cast<rep>(r)}
     {
     }