From ea9d5b0962978fe09d9b08f5729e4881a61726ff Mon Sep 17 00:00:00 2001
From: John Wellbelove <john.wellbelove@etlcpp.com>
Date: Tue, 16 Apr 2024 09:02:59 +0100
Subject: [PATCH] Changes for OSX + C++20 + STL compatibility

---
 include/etl/private/variant_variadic.h |  2 +-
 test/UnitTest++/Checks.h               | 25 ++++++++++++++++++++-----
 test/test_variant_variadic.cpp         |  2 +-
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/include/etl/private/variant_variadic.h b/include/etl/private/variant_variadic.h
index 97f8ce88d..d1543f701 100644
--- a/include/etl/private/variant_variadic.h
+++ b/include/etl/private/variant_variadic.h
@@ -2010,7 +2010,7 @@ namespace etl
   /// Only defined if using C++20 and STL.
   /// https://en.cppreference.com/w/cpp/utility/variant/operator_cmp
   //***************************************************************************
-#if ETL_USING_CPP20 && ETL_USING_STL
+#if ETL_USING_CPP20 && ETL_USING_STL && !(defined(ETL_DEVELOPMENT_OS_APPLE) && defined(ETL_COMPILER_CLANG))
   template <typename... TTypes>
   ETL_CONSTEXPR14 
   std::common_comparison_category_t<std::compare_three_way_result_t<TTypes>...>
diff --git a/test/UnitTest++/Checks.h b/test/UnitTest++/Checks.h
index 88f1a1c30..501ab7ff5 100644
--- a/test/UnitTest++/Checks.h
+++ b/test/UnitTest++/Checks.h
@@ -34,7 +34,7 @@ namespace UnitTest
   template <>
   inline std::string DisplayValue(const char& c)
   {
-    using type = std::char_traits<char>::int_type;
+    typedef std::char_traits<char>::int_type type;
 
     std::ostringstream oss;
 
@@ -47,7 +47,7 @@ namespace UnitTest
   template <>
   inline std::string DisplayValue(const char8_t& c)
   {
-    using type = std::char_traits<char8_t>::int_type;
+    typedef std::char_traits<char8_t>::int_type type;
 
     std::ostringstream oss;
 
@@ -60,7 +60,7 @@ namespace UnitTest
   template <>
   inline std::string DisplayValue(const wchar_t& c)
   {
-    using type = std::char_traits<wchar_t>::int_type;
+    typedef std::char_traits<wchar_t>::int_type type;
 
     std::ostringstream oss;
 
@@ -73,7 +73,7 @@ namespace UnitTest
   template <>
   inline std::string DisplayValue(const char16_t& c)
   {
-    using type = std::char_traits<char16_t>::int_type;
+    typedef std::char_traits<char16_t>::int_type type;
 
     std::ostringstream oss;
 
@@ -85,7 +85,7 @@ namespace UnitTest
   template <>
   inline std::string DisplayValue(const char32_t& c)
   {
-    using type = std::char_traits<char32_t>::int_type;
+    typedef std::char_traits<char32_t>::int_type type;
 
     std::ostringstream oss;
 
@@ -171,6 +171,7 @@ namespace UnitTest
      return !value;
    }
 
+#if __cplusplus >= 201103L
    template< typename Expected, typename Actual >
    void CheckEqual(TestResults& results, Expected&& expected, Actual&& actual, TestDetails const& details)
    {
@@ -183,6 +184,20 @@ namespace UnitTest
        results.OnTestFailure(details, stream.GetText());
      }
    }
+#else
+   template< typename Expected, typename Actual >
+   void CheckEqual(TestResults& results, Expected const& expected, Actual const& actual, TestDetails const& details)
+   {
+     if (!(expected == actual))
+     {
+       UnitTest::MemoryOutStream stream;
+       stream << "Expected "
+         << DisplayValue(expected) << " but was " << DisplayValue(actual);
+
+       results.OnTestFailure(details, stream.GetText());
+     }
+   }
+#endif
 
    template< typename Expected, typename Actual >
    void CheckEqualHex(TestResults& results, Expected const& expected, Actual const& actual, TestDetails const& details)
diff --git a/test/test_variant_variadic.cpp b/test/test_variant_variadic.cpp
index 6a7f94696..a9a7331ee 100644
--- a/test/test_variant_variadic.cpp
+++ b/test/test_variant_variadic.cpp
@@ -2009,7 +2009,7 @@ namespace
     }
 #endif
 
-#if ETL_USING_CPP20 && ETL_USING_STL
+#if ETL_USING_CPP20 && ETL_USING_STL && !(defined(ETL_DEVELOPMENT_OS_APPLE) && defined(ETL_COMPILER_CLANG))
     //*************************************************************************
     TEST(test_variant_spaceship_operator)
     {