ladies and gentlemen we have C++20 concepts in HLSL !

Author: devsh

include/nbl/builtin/hlsl/concepts.hlsl

@@ -1,23 +1,40 @@
-// Copyright (C) 2023 - DevSH Graphics Programming Sp. z O.O.
+// Copyright (C) 2023-2024 - DevSH Graphics Programming Sp. z O.O.
 // This file is part of the "Nabla Engine".
 // For conditions of distribution and use, see copyright notice in nabla.h
-
 #ifndef _NBL_BUILTIN_HLSL_CONCEPTS_INCLUDED_
 #define _NBL_BUILTIN_HLSL_CONCEPTS_INCLUDED_
 
+
 #include <nbl/builtin/hlsl/cpp_compat/vector.hlsl>
 #include <nbl/builtin/hlsl/cpp_compat/matrix.hlsl>
 #include <nbl/builtin/hlsl/type_traits.hlsl>
 
 
-#if (__cplusplus >= 202002L && __cpp_concepts)
+#ifndef __HLSL_VERSION
 
+// TODO: old stuff, see how much we can remove
 #define NBL_CONCEPT_TYPE_PARAMS(...) template <__VA_ARGS__>
 #define NBL_CONCEPT_SIGNATURE(NAME, ...) concept NAME = requires(__VA_ARGS__)
 #define NBL_CONCEPT_BODY(...) { __VA_ARGS__ };
 #define NBL_CONCEPT_ASSIGN(NAME, ...) concept NAME = __VA_ARGS__;
 #define NBL_REQUIRES(...) requires __VA_ARGS__ 
 
+// for struct definitions, use instead of closing `>` on the primary template parameter list
+#define NBL_PRIMARY_REQUIRES(...) > requires (__VA_ARGS__)
+
+// to put right before the closing `>` of the primary template definition, otherwise `NBL_PARTIAL_REQUIRES` wont work on specializations
+#define NBL_STRUCT_CONSTRAINABLE
+// NOTE: C++20 requires and C++11 enable_if have to be in different places! ITS OF UTTMOST IMPORTANCE YOUR REQUIRE CLAUSES ARE IDENTICAL FOR BOTH MACROS
+// put just after the closing `>` on the partial template specialization `template` declaration e.g. `template<typename U, typename V, typename T> NBL_PARTIAL_REQ_TOP(SomeCond<U>)
+#define NBL_PARTIAL_REQ_TOP(...) requires (__VA_ARGS__)
+// put just before closing `>` on the partial template specialization Type args, e.g. `MyStruct<U,V,T NBL_PARTIAL_REQ_BOT(SomeCond<U>)>
+#define NBL_PARTIAL_REQ_BOT(...)
+
+// condition
+#define NBL_FUNC_REQUIRES_BEGIN(...) requires (__VA_ARGS__)
+// return value
+#define NBL_FUNC_REQUIRES_END(...) __VA_ARGS__
+
 #include <concepts>
 
 namespace nbl
@@ -77,12 +94,31 @@ concept matricial = is_matrix<T>::value;
 
 #else
 
+// TODO: old stuff, see how much we can remove
 // No C++20 support. Do nothing.
 #define NBL_CONCEPT_TYPE_PARAMS(...)
 #define NBL_CONCEPT_SIGNATURE(NAME, ...) 
 #define NBL_CONCEPT_BODY(...)
 #define NBL_REQUIRES(...)
 
+
+// for struct definitions, use instead of closing `>` on the primary template parameter list
+#define NBL_PRIMARY_REQUIRES(...) ,typename __requires=::nbl::hlsl::enable_if_t<(__VA_ARGS__),void> > 
+
+// to put right before the closing `>` of the primary template definition, otherwise `NBL_PARTIAL_REQUIRES` wont work on specializations
+#define NBL_STRUCT_CONSTRAINABLE ,typename __requires=void
+// NOTE: C++20 requires and C++11 enable_if have to be in different places! ITS OF UTTMOST IMPORTANCE YOUR REQUIRE CLAUSES ARE IDENTICAL FOR BOTH MACROS
+// put just after the closing `>` on the partial template specialization `template` declaration e.g. `template<typename U, typename V, typename T> NBL_PARTIAL_REQ_TOP(SomeCond<U>)
+#define NBL_PARTIAL_REQ_TOP(...)
+// put just before closing `>` on the partial template specialization Type args, e.g. `MyStruct<U,V,T NBL_PARTIAL_REQ_BOT(SomeCond<U>)>
+#define NBL_PARTIAL_REQ_BOT(...) ,std::enable_if_t<(__VA_ARGS__),void> 
+
+// condition, use right after the closing `>` of a function template
+#define NBL_FUNC_REQUIRES_BEGIN(...) ::nbl::hlsl::enable_if_t<(__VA_ARGS__),
+// return value, use `END(T)` instead of the return value type declaration
+#define NBL_FUNC_REQUIRES_END(...) __VA_ARGS__> 
+
 #endif
 
+
 #endif