From e5d2b95a1b22cfba243f48094c684f5ff588fd32 Mon Sep 17 00:00:00 2001
From: Mateusz Pusz <mateusz.pusz@gmail.com>
Date: Wed, 5 Feb 2025 18:16:15 +0100
Subject: [PATCH] fix: `std::isnan` compilation fixed for freestanding and
 C++20

---
 test/static/limits_test.cpp | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/test/static/limits_test.cpp b/test/static/limits_test.cpp
index 240487082..7338fab32 100644
--- a/test/static/limits_test.cpp
+++ b/test/static/limits_test.cpp
@@ -26,6 +26,9 @@
 import std;
 #else
 #include <limits>
+#if MP_UNITS_HOSTED
+#include <cmath>
+#endif  // MP_UNITS_HOSTED
 #endif
 
 namespace {
@@ -94,12 +97,16 @@ static_assert(std::numeric_limits<q_double>::infinity().numerical_value_in(mp_un
 static_assert(std::numeric_limits<q_int>::infinity().numerical_value_in(mp_units::si::metre) ==
               std::numeric_limits<int>::infinity());
 
+#if MP_UNITS_HOSTED && (__cpp_lib_constexpr_cmath || MP_UNITS_COMP_GCC)
+
 // quiet_NaN
 static_assert(std::isnan(std::numeric_limits<q_double>::quiet_NaN().numerical_value_in(mp_units::si::metre)));
 
 // signaling_NaN
 static_assert(std::isnan(std::numeric_limits<q_double>::signaling_NaN().numerical_value_in(mp_units::si::metre)));
 
+#endif
+
 // denorm_min
 static_assert(std::numeric_limits<q_double>::denorm_min().numerical_value_in(mp_units::si::metre) ==
               std::numeric_limits<double>::denorm_min());
@@ -171,6 +178,8 @@ static_assert(std::numeric_limits<qp_double>::infinity().quantity_from_zero().nu
 static_assert(std::numeric_limits<qp_int>::infinity().quantity_from_zero().numerical_value_in(mp_units::si::metre) ==
               std::numeric_limits<int>::infinity());
 
+#if MP_UNITS_HOSTED && (__cpp_lib_constexpr_cmath || MP_UNITS_COMP_GCC)
+
 // quiet_NaN
 static_assert(
   std::isnan(std::numeric_limits<qp_double>::quiet_NaN().quantity_from_zero().numerical_value_in(mp_units::si::metre)));
@@ -179,6 +188,8 @@ static_assert(
 static_assert(std::isnan(
   std::numeric_limits<qp_double>::signaling_NaN().quantity_from_zero().numerical_value_in(mp_units::si::metre)));
 
+#endif
+
 // denorm_min
 static_assert(std::numeric_limits<qp_double>::denorm_min().quantity_from_zero().numerical_value_in(
                 mp_units::si::metre) == std::numeric_limits<double>::denorm_min());