From 37a3175abf87e2922c799d4baf49513ba0c4212c Mon Sep 17 00:00:00 2001
From: Alex Dewar <alexdewar@users.noreply.github.com>
Date: Thu, 8 Oct 2020 00:00:52 +0100
Subject: [PATCH] Make unarary ``operator+()`` and ``operator-()``
 ``constexpr`` (#226)

Co-authored-by: Nic Holthaus <nholthaus@gmail.com>
---
 include/units.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/units.h b/include/units.h
index c789939c..e1c6136f 100644
--- a/include/units.h
+++ b/include/units.h
@@ -2309,7 +2309,7 @@ namespace units
 
 	// unary addition: +T
 	template<class Units, typename T, template<typename> class NonLinearScale>
-	inline unit_t<Units, T, NonLinearScale> operator+(const unit_t<Units, T, NonLinearScale>& u) noexcept
+	constexpr inline unit_t<Units, T, NonLinearScale> operator+(const unit_t<Units, T, NonLinearScale>& u) noexcept
 	{
 		return u;
 	}
@@ -2333,7 +2333,7 @@ namespace units
 
 	// unary addition: -T
 	template<class Units, typename T, template<typename> class NonLinearScale>
-	inline unit_t<Units, T, NonLinearScale> operator-(const unit_t<Units, T, NonLinearScale>& u) noexcept
+	constexpr inline unit_t<Units, T, NonLinearScale> operator-(const unit_t<Units, T, NonLinearScale>& u) noexcept
 	{
 		return unit_t<Units, T, NonLinearScale>(-u());
 	}