1 files changed, 75 insertions, 0 deletions
diff --git a/src/catch2/internal/catch_compare_traits.hpp b/src/catch2/internal/catch_compare_traits.hpp
new file mode 100644
index 0000000..6304b1f
--- /dev/null
+++ b/src/catch2/internal/catch_compare_traits.hpp
@@ -0,0 +1,75 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+#ifndef CATCH_COMPARE_TRAITS_HPP_INCLUDED
+#define CATCH_COMPARE_TRAITS_HPP_INCLUDED
+
+#include <catch2/internal/catch_void_type.hpp>
+
+#include <type_traits>
+
+namespace Catch {
+    namespace Detail {
+
+#if defined( __GNUC__ ) && !defined( __clang__ )
+#    pragma GCC diagnostic push
+    // GCC likes to complain about comparing bool with 0, in the decltype()
+    // that defines the comparable traits below.
+#    pragma GCC diagnostic ignored "-Wbool-compare"
+    // "ordered comparison of pointer with integer zero" same as above,
+    // but it does not have a separate warning flag to suppress
+#    pragma GCC diagnostic ignored "-Wextra"
+    // Did you know that comparing floats with `0` directly
+    // is super-duper dangerous in unevaluated context?
+#    pragma GCC diagnostic ignored "-Wfloat-equal"
+#endif
+
+#if defined( __clang__ )
+#    pragma clang diagnostic push
+    // Did you know that comparing floats with `0` directly
+    // is super-duper dangerous in unevaluated context?
+#    pragma clang diagnostic ignored "-Wfloat-equal"
+#endif
+
+#define CATCH_DEFINE_COMPARABLE_TRAIT( id, op )                               \
+    template <typename, typename, typename = void>                            \
+    struct is_##id##_comparable : std::false_type {};                         \
+    template <typename T, typename U>                                         \
+    struct is_##id##_comparable<                                              \
+        T,                                                                    \
+        U,                                                                    \
+        void_t<decltype( std::declval<T>() op std::declval<U>() )>>           \
+        : std::true_type {};                                                  \
+    template <typename, typename = void>                                      \
+    struct is_##id##_0_comparable : std::false_type {};                       \
+    template <typename T>                                                     \
+    struct is_##id##_0_comparable<T,                                          \
+                                  void_t<decltype( std::declval<T>() op 0 )>> \
+        : std::true_type {};
+
+        // We need all 6 pre-spaceship comparison ops: <, <=, >, >=, ==, !=
+        CATCH_DEFINE_COMPARABLE_TRAIT( lt, < )
+        CATCH_DEFINE_COMPARABLE_TRAIT( le, <= )
+        CATCH_DEFINE_COMPARABLE_TRAIT( gt, > )
+        CATCH_DEFINE_COMPARABLE_TRAIT( ge, >= )
+        CATCH_DEFINE_COMPARABLE_TRAIT( eq, == )
+        CATCH_DEFINE_COMPARABLE_TRAIT( ne, != )
+
+#undef CATCH_DEFINE_COMPARABLE_TRAIT
+
+#if defined( __GNUC__ ) && !defined( __clang__ )
+#    pragma GCC diagnostic pop
+#endif
+#if defined( __clang__ )
+#    pragma clang diagnostic pop
+#endif
+
+
+    } // namespace Detail
+} // namespace Catch
+
+#endif // CATCH_COMPARE_TRAITS_HPP_INCLUDED