Add logical trait polyfills

src/CMakeLists.txt

@@ -91,6 +91,7 @@ set(IMPL_HEADERS
   ${SOURCES_DIR}/internal/catch_lazy_expr.hpp
   ${SOURCES_DIR}/internal/catch_leak_detector.hpp
   ${SOURCES_DIR}/internal/catch_list.hpp
+  ${SOURCES_DIR}/internal/catch_logical_traits.hpp
   ${SOURCES_DIR}/internal/catch_message_info.hpp
   ${SOURCES_DIR}/internal/catch_meta.hpp
   ${SOURCES_DIR}/internal/catch_move_and_forward.hpp

src/catch2/catch_all.hpp

@@ -74,6 +74,7 @@
 #include <catch2/internal/catch_lazy_expr.hpp>
 #include <catch2/internal/catch_leak_detector.hpp>
 #include <catch2/internal/catch_list.hpp>
+#include <catch2/internal/catch_logical_traits.hpp>
 #include <catch2/internal/catch_message_info.hpp>
 #include <catch2/internal/catch_meta.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>

src/catch2/internal/catch_logical_traits.hpp

@@ -0,0 +1,44 @@
+
+//              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_LOGICAL_TRAITS_HPP_INCLUDED
+#define CATCH_LOGICAL_TRAITS_HPP_INCLUDED
+
+#include <type_traits>
+
+namespace Catch {
+namespace Detail {
+
+#if defined( __cpp_lib_logical_traits ) && __cpp_lib_logical_traits >= 201510
+
+    using std::conjunction;
+    using std::disjunction;
+    using std::negation;
+
+#else
+
+    template <class...> struct conjunction : std::true_type {};
+    template <class B1> struct conjunction<B1> : B1 {};
+    template <class B1, class... Bn>
+    struct conjunction<B1, Bn...>
+        : std::conditional_t<bool( B1::value ), conjunction<Bn...>, B1> {};
+
+    template <class...> struct disjunction : std::false_type {};
+    template <class B1> struct disjunction<B1> : B1 {};
+    template <class B1, class... Bn>
+    struct disjunction<B1, Bn...>
+        : std::conditional_t<bool( B1::value ), B1, disjunction<Bn...>> {};
+
+    template <class B>
+    struct negation : std::integral_constant<bool, !bool(B::value)> {};
+
+#endif
+
+} // namespace Detail
+} // namespace Catch
+
+#endif // CATCH_LOGICAL_TRAITS_HPP_INCLUDED

src/catch2/matchers/catch_matchers_templated.hpp

@@ -11,6 +11,7 @@
 #include <catch2/matchers/catch_matchers.hpp>
 #include <catch2/internal/catch_stringref.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
+#include <catch2/internal/catch_logical_traits.hpp>
 
 #include <array>
 #include <algorithm>
@@ -56,20 +57,6 @@ namespace Matchers {
             return arr;
         }
 
-#if defined( __cpp_lib_logical_traits ) && __cpp_lib_logical_traits >= 201510
-
-        using std::conjunction;
-
-#else // __cpp_lib_logical_traits
-
-        template<typename... Cond>
-        struct conjunction : std::true_type {};
-
-        template<typename Cond, typename... Rest>
-        struct conjunction<Cond, Rest...> : std::integral_constant<bool, Cond::value && conjunction<Rest...>::value> {};
-
-#endif // __cpp_lib_logical_traits
-
         template<typename T>
         using is_generic_matcher = std::is_base_of<
             Catch::Matchers::MatcherGenericBase,
@@ -77,7 +64,7 @@ namespace Matchers {
         >;
 
         template<typename... Ts>
-        using are_generic_matchers = conjunction<is_generic_matcher<Ts>...>;
+        using are_generic_matchers = Catch::Detail::conjunction<is_generic_matcher<Ts>...>;
 
         template<typename T>
         using is_matcher = std::is_base_of<

src/catch2/meson.build

@@ -96,6 +96,7 @@ internal_headers = [
   'internal/catch_lazy_expr.hpp',
   'internal/catch_leak_detector.hpp',
   'internal/catch_list.hpp',
+  'internal/catch_logical_traits.hpp',
   'internal/catch_message_info.hpp',
   'internal/catch_meta.hpp',
   'internal/catch_move_and_forward.hpp',