From 71eda2fc66724e3e5a28e3bd71b4bbb37da22aa6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johel=20Ernesto=20Guerrero=20Pe=C3=B1a?=
 <johelegp@gmail.com>
Date: Sat, 5 Sep 2020 22:22:18 -0400
Subject: [PATCH] test: codify comment in the correct place

---
 test/unit_test/static/quantity_test.cpp | 2 --
 test/unit_test/static/unit_test.cpp     | 3 +++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/test/unit_test/static/quantity_test.cpp b/test/unit_test/static/quantity_test.cpp
index 3e80b688..dcc9d7bf 100644
--- a/test/unit_test/static/quantity_test.cpp
+++ b/test/unit_test/static/quantity_test.cpp
@@ -36,8 +36,6 @@ using namespace units::physical::si;
 
 // class invariants
 
-// constexpr quantity<si::dim_length, scaled_unit<ratio(-1, 1), metre>, int> error(0);  // should not compile (negative unit ratio)
-
 template<typename DimLength>
 concept invalid_types = requires
 {
diff --git a/test/unit_test/static/unit_test.cpp b/test/unit_test/static/unit_test.cpp
index a48a1e86..125db502 100644
--- a/test/unit_test/static/unit_test.cpp
+++ b/test/unit_test/static/unit_test.cpp
@@ -51,6 +51,9 @@ static_assert(is_same_v<downcast<scaled_unit<ratio(1, 1, -2), metre>>, centimetr
 static_assert(is_same_v<downcast<scaled_unit<ratio(yard::ratio.num, yard::ratio.den, yard::ratio.exp), metre>>, yard>);
 static_assert(is_same_v<downcast<scaled_unit<yard::ratio * ratio(1, 3), metre>>, foot>);
 static_assert(is_same_v<downcast<scaled_unit<kilometre::ratio / hour::ratio, metre_per_second>>, kilometre_per_hour>);
+#if COMP_MSVC || COMP_GCC >= 10
+static_assert([]<ratio R>() { return !requires { typename scaled_unit<R, metre>; }; }.template operator()<ratio(-1, 1)>()); // negative unit ratio
+#endif
 
 static_assert(centimetre::symbol == "cm");
 static_assert(kilometre::symbol == "km");