is_specialization_of_v, is_monad_trait_v, is_evm_trait_v

Author: zander-xyz

category/core/CMakeLists.txt

@@ -66,8 +66,7 @@ check_if_boost_fiber_needs_ucontext_macro()
 # ##############################################################################
 
 add_library(
-  monad_core
-  OBJECT
+  monad_core OBJECT
   # config
   "config.hpp"
   # core
@@ -89,6 +88,7 @@ add_library(
   "hash.hpp"
   "hex_literal.hpp"
   "int.hpp"
+  "is_specialization_of.hpp"
   "keccak.c"
   "keccak.h"
   "keccak.hpp"

category/core/is_specialization_of.hpp

@@ -0,0 +1,38 @@
+// Copyright (C) 2025 Category Labs, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2098r0.pdf
+
+#pragma once
+
+#include <category/core/config.hpp>
+
+MONAD_NAMESPACE_BEGIN
+
+template <template <auto...> class Template, typename T>
+struct is_specialization_of : std::false_type
+{
+};
+
+template <template <auto...> class Template, auto... Args>
+struct is_specialization_of<Template, Template<Args...>> : std::true_type
+{
+};
+
+template <template <auto...> class Template, typename T>
+inline constexpr bool is_specialization_of_v =
+    is_specialization_of<Template, T>::value;
+
+MONAD_NAMESPACE_END

category/execution/ethereum/evm_test.cpp

@@ -688,11 +688,11 @@ TYPED_TEST(TraitsTest, create_inside_delegated_call)
         auto const result = h.call(m);
         // CREATE should fail on Monad chains and succeed on Ethereum chains
         if constexpr (TestFixture::Trait::can_create_inside_delegated()) {
-            static_assert(TestFixture::is_evmc_revision());
+            static_assert(TestFixture::is_evm_trait());
             EXPECT_EQ(result.status_code, EVMC_SUCCESS);
         }
         else {
-            static_assert(TestFixture::is_monad_revision());
+            static_assert(TestFixture::is_monad_trait());
             EXPECT_EQ(result.status_code, EVMC_FAILURE);
         }
     }
@@ -802,11 +802,11 @@ TYPED_TEST(TraitsTest, create2_inside_delegated_call_via_delegatecall)
         auto const result = h.call(m);
         // CREATE2 should fail on Monad chains and succeed on Ethereum chains
         if constexpr (TestFixture::Trait::can_create_inside_delegated()) {
-            static_assert(TestFixture::is_evmc_revision());
+            static_assert(TestFixture::is_evm_trait());
             EXPECT_EQ(result.status_code, EVMC_SUCCESS);
         }
         else {
-            static_assert(TestFixture::is_monad_revision());
+            static_assert(TestFixture::is_monad_trait());
             EXPECT_EQ(result.status_code, EVMC_FAILURE);
         }
     }

category/vm/evm/traits.hpp

@@ -15,6 +15,7 @@
 
 #pragma once
 
+#include <category/core/is_specialization_of.hpp>
 #include <category/vm/core/assert.h>
 #include <category/vm/evm/monad/revision.h>
 
@@ -289,4 +290,16 @@ namespace monad
         // complete.
         using evm_base = EvmTraits<MonadTraits::evm_rev()>;
     };
+
+    template <typename T>
+    inline constexpr bool is_evm_trait_v = is_specialization_of_v<EvmTraits, T>;
+
+    template <typename T>
+    inline constexpr bool is_monad_trait_v =
+        is_specialization_of_v<MonadTraits, T>;
+
+    static_assert(is_monad_trait_v<MonadTraits<MONAD_ZERO>> == true);
+    static_assert(is_monad_trait_v<EvmTraits<EVMC_FRONTIER>> == false);
+    static_assert(is_evm_trait_v<MonadTraits<MONAD_ZERO>> == false);
+    static_assert(is_evm_trait_v<EvmTraits<EVMC_FRONTIER>> == true);
 }

test/unit/common/include/monad/test/traits_test.hpp

@@ -122,17 +122,17 @@ struct TraitsTest : public ::testing::Test
         }
     }
 
-    static consteval bool is_monad_revision() noexcept
+    using Trait = decltype(get_trait());
+
+    static consteval bool is_monad_trait() noexcept
     {
-        return std::same_as<typename T::value_type, monad_revision>;
+        return monad::is_monad_trait_v<Trait>;
     }
 
-    static consteval bool is_evmc_revision() noexcept
+    static consteval bool is_evm_trait() noexcept
     {
-        return std::same_as<typename T::value_type, evmc_revision>;
+        return monad::is_evm_trait_v<Trait>;
     }
-
-    using Trait = decltype(get_trait());
 };
 
 TYPED_TEST_SUITE(