Use variable templates

src/catch2/benchmark/catch_benchmark.hpp

@@ -97,7 +97,7 @@ namespace Catch {
             }
 
             // sets lambda to be used in fun *and* executes benchmark!
-            template <typename Fun, std::enable_if_t<!Detail::is_related<Fun, Benchmark>::value, int> = 0>
+            template <typename Fun, std::enable_if_t<!Detail::is_related_v<Fun, Benchmark>, int> = 0>
                 Benchmark & operator=(Fun func) {
                 auto const* cfg = getCurrentContext().getConfig();
                 if (!cfg->skipBenchmarks()) {

src/catch2/benchmark/detail/catch_benchmark_function.hpp

@@ -21,8 +21,7 @@ namespace Catch {
     namespace Benchmark {
         namespace Detail {
             template <typename T, typename U>
-            struct is_related
-                : std::is_same<std::decay_t<T>, std::decay_t<U>> {};
+            static constexpr bool is_related_v = std::is_same<std::decay_t<T>, std::decay_t<U>>::value;
 
             /// We need to reinvent std::function because every piece of code that might add overhead
             /// in a measurement context needs to have consistent performance characteristics so that we
@@ -63,7 +62,7 @@ namespace Catch {
                 BenchmarkFunction();
 
                 template <typename Fun,
-                    std::enable_if_t<!is_related<Fun, BenchmarkFunction>::value, int> = 0>
+                    std::enable_if_t<!is_related_v<Fun, BenchmarkFunction>, int> = 0>
                     BenchmarkFunction(Fun&& fun)
                     : f(new model<std::decay_t<Fun>>(CATCH_FORWARD(fun))) {}
 

src/catch2/catch_tostring.hpp

@@ -64,18 +64,14 @@ namespace Catch {
           return rawMemoryToString( &object, sizeof(object) );
         }
 
-        template<typename T>
-        class IsStreamInsertable {
-            template<typename Stream, typename U>
-            static auto test(int)
-                -> decltype(std::declval<Stream&>() << std::declval<U>(), std::true_type());
+        template<typename T,typename = void>
+        static constexpr bool IsStreamInsertable_v = false;
 
-            template<typename, typename>
-            static auto test(...)->std::false_type;
-
-        public:
-            static const bool value = decltype(test<std::ostream, const T&>(0))::value;
-        };
+        template <typename T>
+        static constexpr bool IsStreamInsertable_v<
+            T,
+            decltype( void( std::declval<std::ostream&>() << std::declval<T>() ) )> =
+            true;
 
         template<typename E>
         std::string convertUnknownEnumToString( E e );
@@ -120,7 +116,7 @@ namespace Catch {
     struct StringMaker {
         template <typename Fake = T>
         static
-        std::enable_if_t<::Catch::Detail::IsStreamInsertable<Fake>::value, std::string>
+        std::enable_if_t<::Catch::Detail::IsStreamInsertable_v<Fake>, std::string>
             convert(const Fake& value) {
                 ReusableStringStream rss;
                 // NB: call using the function-like syntax to avoid ambiguity with
@@ -131,7 +127,7 @@ namespace Catch {
 
         template <typename Fake = T>
         static
-        std::enable_if_t<!::Catch::Detail::IsStreamInsertable<Fake>::value, std::string>
+        std::enable_if_t<!::Catch::Detail::IsStreamInsertable_v<Fake>, std::string>
             convert( const Fake& value ) {
 #if !defined(CATCH_CONFIG_FALLBACK_STRINGIFIER)
             return Detail::convertUnstreamable(value);
@@ -523,7 +519,7 @@ namespace Catch {
     }
 
     template<typename R>
-    struct StringMaker<R, std::enable_if_t<is_range<R>::value && !::Catch::Detail::IsStreamInsertable<R>::value>> {
+    struct StringMaker<R, std::enable_if_t<is_range<R>::value && !::Catch::Detail::IsStreamInsertable_v<R>>> {
         static std::string convert( R const& range ) {
             return rangeToString( range );
         }

src/catch2/matchers/catch_matchers_container_properties.hpp

@@ -79,7 +79,7 @@ namespace Catch {
         //! Creates a matcher that accepts ranges/containers with specific size
         HasSizeMatcher SizeIs(std::size_t sz);
         template <typename Matcher>
-        std::enable_if_t<Detail::is_matcher<Matcher>::value,
+        std::enable_if_t<Detail::is_matcher_v<Matcher>,
         SizeMatchesMatcher<Matcher>> SizeIs(Matcher&& m) {
             return SizeMatchesMatcher<Matcher>{CATCH_FORWARD(m)};
         }

src/catch2/matchers/catch_matchers_contains.hpp

@@ -73,14 +73,14 @@ namespace Catch {
          * Uses `std::equal_to` to do the comparison
          */
         template <typename T>
-        std::enable_if_t<!Detail::is_matcher<T>::value,
+        std::enable_if_t<!Detail::is_matcher_v<T>,
         ContainsElementMatcher<T, std::equal_to<>>> Contains(T&& elem) {
             return { CATCH_FORWARD(elem), std::equal_to<>{} };
         }
 
         //! Creates a matcher that checks whether a range contains element matching a matcher
         template <typename Matcher>
-        std::enable_if_t<Detail::is_matcher<Matcher>::value,
+        std::enable_if_t<Detail::is_matcher_v<Matcher>,
         ContainsMatcherMatcher<Matcher>> Contains(Matcher&& matcher) {
             return { CATCH_FORWARD(matcher) };
         }

src/catch2/matchers/catch_matchers_templated.hpp

@@ -58,19 +58,19 @@ namespace Matchers {
         }
 
         template<typename T>
-        using is_generic_matcher = std::is_base_of<
+        static constexpr bool is_generic_matcher_v = std::is_base_of<
             Catch::Matchers::MatcherGenericBase,
             std::remove_cv_t<std::remove_reference_t<T>>
-        >;
+        >::value;
 
         template<typename... Ts>
-        using are_generic_matchers = Catch::Detail::conjunction<is_generic_matcher<Ts>...>;
+        static constexpr bool are_generic_matchers_v = Catch::Detail::conjunction<std::integral_constant<bool,is_generic_matcher_v<Ts>>...>::value;
 
         template<typename T>
-        using is_matcher = std::is_base_of<
+        static constexpr bool is_matcher_v = std::is_base_of<
             Catch::Matchers::MatcherUntypedBase,
             std::remove_cv_t<std::remove_reference_t<T>>
-        >;
+        >::value;
 
 
         template<std::size_t N, typename Arg>
@@ -143,7 +143,7 @@ namespace Matchers {
 
             //! Avoids type nesting for `GenericAllOf && some matcher` case
             template<typename MatcherRHS>
-            friend std::enable_if_t<is_matcher<MatcherRHS>::value,
+            friend std::enable_if_t<is_matcher_v<MatcherRHS>,
             MatchAllOfGeneric<MatcherTs..., MatcherRHS>> operator && (
                     MatchAllOfGeneric<MatcherTs...>&& lhs,
                     MatcherRHS const& rhs) {
@@ -152,7 +152,7 @@ namespace Matchers {
 
             //! Avoids type nesting for `some matcher && GenericAllOf` case
             template<typename MatcherLHS>
-            friend std::enable_if_t<is_matcher<MatcherLHS>::value,
+            friend std::enable_if_t<is_matcher_v<MatcherLHS>,
             MatchAllOfGeneric<MatcherLHS, MatcherTs...>> operator && (
                     MatcherLHS const& lhs,
                     MatchAllOfGeneric<MatcherTs...>&& rhs) {
@@ -197,7 +197,7 @@ namespace Matchers {
 
             //! Avoids type nesting for `GenericAnyOf || some matcher` case
             template<typename MatcherRHS>
-            friend std::enable_if_t<is_matcher<MatcherRHS>::value,
+            friend std::enable_if_t<is_matcher_v<MatcherRHS>,
             MatchAnyOfGeneric<MatcherTs..., MatcherRHS>> operator || (
                     MatchAnyOfGeneric<MatcherTs...>&& lhs,
                     MatcherRHS const& rhs) {
@@ -206,7 +206,7 @@ namespace Matchers {
 
             //! Avoids type nesting for `some matcher || GenericAnyOf` case
             template<typename MatcherLHS>
-            friend std::enable_if_t<is_matcher<MatcherLHS>::value,
+            friend std::enable_if_t<is_matcher_v<MatcherLHS>,
             MatchAnyOfGeneric<MatcherLHS, MatcherTs...>> operator || (
                 MatcherLHS const& lhs,
                 MatchAnyOfGeneric<MatcherTs...>&& rhs) {
@@ -246,20 +246,20 @@ namespace Matchers {
 
     // compose only generic matchers
     template<typename MatcherLHS, typename MatcherRHS>
-    std::enable_if_t<Detail::are_generic_matchers<MatcherLHS, MatcherRHS>::value, Detail::MatchAllOfGeneric<MatcherLHS, MatcherRHS>>
+    std::enable_if_t<Detail::are_generic_matchers_v<MatcherLHS, MatcherRHS>, Detail::MatchAllOfGeneric<MatcherLHS, MatcherRHS>>
         operator && (MatcherLHS const& lhs, MatcherRHS const& rhs) {
         return { lhs, rhs };
     }
 
     template<typename MatcherLHS, typename MatcherRHS>
-    std::enable_if_t<Detail::are_generic_matchers<MatcherLHS, MatcherRHS>::value, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherRHS>>
+    std::enable_if_t<Detail::are_generic_matchers_v<MatcherLHS, MatcherRHS>, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherRHS>>
         operator || (MatcherLHS const& lhs, MatcherRHS const& rhs) {
         return { lhs, rhs };
     }
 
     //! Wrap provided generic matcher in generic negator
     template<typename MatcherT>
-    std::enable_if_t<Detail::is_generic_matcher<MatcherT>::value, Detail::MatchNotOfGeneric<MatcherT>>
+    std::enable_if_t<Detail::is_generic_matcher_v<MatcherT>, Detail::MatchNotOfGeneric<MatcherT>>
         operator ! (MatcherT const& matcher) {
         return Detail::MatchNotOfGeneric<MatcherT>{matcher};
     }
@@ -267,25 +267,25 @@ namespace Matchers {
 
     // compose mixed generic and non-generic matchers
     template<typename MatcherLHS, typename ArgRHS>
-    std::enable_if_t<Detail::is_generic_matcher<MatcherLHS>::value, Detail::MatchAllOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
+    std::enable_if_t<Detail::is_generic_matcher_v<MatcherLHS>, Detail::MatchAllOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
         operator && (MatcherLHS const& lhs, MatcherBase<ArgRHS> const& rhs) {
         return { lhs, rhs };
     }
 
     template<typename ArgLHS, typename MatcherRHS>
-    std::enable_if_t<Detail::is_generic_matcher<MatcherRHS>::value, Detail::MatchAllOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
+    std::enable_if_t<Detail::is_generic_matcher_v<MatcherRHS>, Detail::MatchAllOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
         operator && (MatcherBase<ArgLHS> const& lhs, MatcherRHS const& rhs) {
         return { lhs, rhs };
     }
 
     template<typename MatcherLHS, typename ArgRHS>
-    std::enable_if_t<Detail::is_generic_matcher<MatcherLHS>::value, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
+    std::enable_if_t<Detail::is_generic_matcher_v<MatcherLHS>, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
         operator || (MatcherLHS const& lhs, MatcherBase<ArgRHS> const& rhs) {
         return { lhs, rhs };
     }
 
     template<typename ArgLHS, typename MatcherRHS>
-    std::enable_if_t<Detail::is_generic_matcher<MatcherRHS>::value, Detail::MatchAnyOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
+    std::enable_if_t<Detail::is_generic_matcher_v<MatcherRHS>, Detail::MatchAnyOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
         operator || (MatcherBase<ArgLHS> const& lhs, MatcherRHS const& rhs) {
         return { lhs, rhs };
     }