add a _CCCL_NO_CONCEPTS config macro (#2945)

Co-authored-by: Bernhard Manfred Gruber <[email protected]>
NVIDIA · Nov 25, 2024 · a085ba1 · a085ba1
1 parent db47d38
commit a085ba1
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Showing 42 changed files with 187 additions and 179 deletions.
diff --git a/libcudacxx/include/cuda/std/__cccl/dialect.h b/libcudacxx/include/cuda/std/__cccl/dialect.h
@@ -80,6 +80,7 @@
 #  define _CCCL_IF_CONSTEXPR      if constexpr
 #  define _CCCL_ELSE_IF_CONSTEXPR else if constexpr
 #else // ^^^ C++17 ^^^ / vvv C++14 vvv
+#  define _CCCL_NO_IF_CONSTEXPR
 #  define _CCCL_IF_CONSTEXPR      if
 #  define _CCCL_ELSE_IF_CONSTEXPR else if
 #endif // _CCCL_STD_VER <= 2014
@@ -104,6 +105,11 @@
 #  define _CCCL_NO_VARIABLE_TEMPLATES
 #endif // _CCCL_STD_VER <= 2011
 
+// concepts are only available from C++20 onwards
+#if _CCCL_STD_VER <= 2017 || !defined(__cpp_concepts) || (__cpp_concepts < 201907L)
+#  define _CCCL_NO_CONCEPTS
+#endif // _CCCL_STD_VER <= 2017 || !defined(__cpp_concepts) || (__cpp_concepts < 201907L)
+
 // noexcept function types are only available from C++17 onwards
 #if _CCCL_STD_VER >= 2017 && defined(__cpp_noexcept_function_type) && (__cpp_noexcept_function_type >= 201510L)
 #  define _CCCL_FUNCTION_TYPE_NOEXCEPT noexcept

diff --git a/libcudacxx/include/cuda/std/__concepts/arithmetic.h b/libcudacxx/include/cuda/std/__concepts/arithmetic.h
@@ -30,7 +30,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2011
+#if !defined(_CCCL_NO_VARIABLE_TEMPLATES)
 
 // [concepts.arithmetic], arithmetic concepts
 
@@ -49,7 +49,7 @@ _CCCL_CONCEPT floating_point = _CCCL_TRAIT(is_floating_point, _Tp);
 template <class _Tp>
 _CCCL_CONCEPT __libcpp_signed_integer = __libcpp_is_signed_integer<_Tp>::value;
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/assignable.h b/libcudacxx/include/cuda/std/__concepts/assignable.h
@@ -29,7 +29,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concept.assignable]
 
@@ -40,7 +40,7 @@ concept assignable_from =
        { __lhs = _CUDA_VSTD::forward<_Rhs>(__rhs) } -> same_as<_Lhs>;
      };
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Lhs, class _Rhs>
 _CCCL_CONCEPT_FRAGMENT(
@@ -53,7 +53,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Lhs, class _Rhs>
 _CCCL_CONCEPT assignable_from = _CCCL_FRAGMENT(__assignable_from_, _Lhs, _Rhs);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/boolean_testable.h b/libcudacxx/include/cuda/std/__concepts/boolean_testable.h
@@ -26,7 +26,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concepts.booleantestable]
 
@@ -38,7 +38,7 @@ concept __boolean_testable = __boolean_testable_impl<_Tp> && requires(_Tp&& __t)
   { !_CUDA_VSTD::forward<_Tp>(__t) } -> __boolean_testable_impl;
 };
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Tp>
 _CCCL_CONCEPT __boolean_testable_impl = convertible_to<_Tp, bool>;
@@ -52,7 +52,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Tp>
 _CCCL_CONCEPT __boolean_testable = _CCCL_FRAGMENT(__boolean_testable_, _Tp);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/class_or_enum.h b/libcudacxx/include/cuda/std/__concepts/class_or_enum.h
@@ -28,7 +28,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2011
+#if !defined(_CCCL_NO_VARIABLE_TEMPLATES)
 
 template <class _Tp>
 _CCCL_CONCEPT __class_or_enum = _CCCL_TRAIT(is_class, _Tp) || _CCCL_TRAIT(is_union, _Tp) || _CCCL_TRAIT(is_enum, _Tp);
@@ -39,7 +39,7 @@ template <class _Tp>
 _CCCL_CONCEPT __workaround_52970 =
   _CCCL_TRAIT(is_class, remove_cvref_t<_Tp>) || _CCCL_TRAIT(is_union, remove_cvref_t<_Tp>);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/common_reference_with.h b/libcudacxx/include/cuda/std/__concepts/common_reference_with.h
@@ -29,7 +29,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concept.commonref]
 
@@ -38,7 +38,7 @@ concept common_reference_with =
   same_as<common_reference_t<_Tp, _Up>, common_reference_t<_Up, _Tp>>
   && convertible_to<_Tp, common_reference_t<_Tp, _Up>> && convertible_to<_Up, common_reference_t<_Tp, _Up>>;
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Tp, class _Up>
 _CCCL_CONCEPT_FRAGMENT(__common_reference_exists_,
@@ -58,7 +58,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Tp, class _Up>
 _CCCL_CONCEPT common_reference_with = _CCCL_FRAGMENT(__common_reference_with_, _Tp, _Up);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/common_with.h b/libcudacxx/include/cuda/std/__concepts/common_with.h
@@ -29,7 +29,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concept.common]
 
@@ -39,7 +39,7 @@ concept common_with = same_as<common_type_t<_Tp, _Up>, common_type_t<_Up, _Tp>>
   static_cast<common_type_t<_Tp, _Up>>(_CUDA_VSTD::declval<_Up>());
 } && common_reference_with<add_lvalue_reference_t<const _Tp>, add_lvalue_reference_t<const _Up>> && common_reference_with<add_lvalue_reference_t<common_type_t<_Tp, _Up>>, common_reference_t<add_lvalue_reference_t<const _Tp>, add_lvalue_reference_t<const _Up>>>;
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Tp, class _Up>
 _CCCL_CONCEPT_FRAGMENT(__common_type_exists_,
@@ -71,7 +71,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Tp, class _Up>
 _CCCL_CONCEPT common_with = _CCCL_FRAGMENT(__common_with_, _Tp, _Up);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/concept_macros.h b/libcudacxx/include/cuda/std/__concepts/concept_macros.h
@@ -52,21 +52,22 @@ using __cccl_enable_if_t = typename __cccl_select<_Bp>::template type<_Tp>;
 template <class _Tp, bool _Bp>
 using __cccl_requires_t = typename __cccl_select<_Bp>::template type<_Tp>;
 
-#if (defined(__cpp_concepts) && _CCCL_STD_VER >= 2020) || defined(_CCCL_DOXYGEN_INVOKED)
+#if !defined(_CCCL_NO_CONCEPTS) || defined(_CCCL_DOXYGEN_INVOKED)
 #  define _CCCL_TEMPLATE(...)               template <__VA_ARGS__>
 #  define _CCCL_REQUIRES(...)               requires __VA_ARGS__
 #  define _CCCL_AND                         &&
 #  define _CCCL_TRAILING_REQUIRES_AUX_(...) requires __VA_ARGS__
 #  define _CCCL_TRAILING_REQUIRES(...)      ->__VA_ARGS__ _CCCL_TRAILING_REQUIRES_AUX_
-#else // ^^^ __cpp_concepts ^^^ / vvv !__cpp_concepts vvv
+#else // ^^^ _CCCL_NO_CONCEPTS ^^^ / vvv !_CCCL_NO_CONCEPTS vvv
 #  define _CCCL_TEMPLATE(...)               template <__VA_ARGS__
 #  define _CCCL_REQUIRES(...)               , bool __cccl_true_ = true, __cccl_enable_if_t < __VA_ARGS__ && __cccl_true_, int > = 0 >
 #  define _CCCL_AND                         &&__cccl_true_, int > = 0, __cccl_enable_if_t <
 #  define _CCCL_TRAILING_REQUIRES_AUX_(...) , __VA_ARGS__ >
 #  define _CCCL_TRAILING_REQUIRES(...)      ->__cccl_requires_t < __VA_ARGS__ _CCCL_TRAILING_REQUIRES_AUX_
-#endif // !__cpp_concepts
+#endif // !defined(_CCCL_NO_CONCEPTS)
 
-#if _CCCL_STD_VER >= 2014
+// The following concepts emulation macros need variable template support
+#if !defined(_CCCL_NO_VARIABLE_TEMPLATES)
 
 template <class...>
 struct __cccl_tag;
@@ -141,7 +142,7 @@ namespace __cccl_unqualified_cuda_std = _CUDA_VSTD; // NOLINT(misc-unused-alias-
 #  define _CCCL_PP_EAT_TYPENAME_SELECT_1(...) _CCCL_PP_CAT3(_CCCL_PP_EAT_TYPENAME_, __VA_ARGS__)
 #  define _CCCL_PP_EAT_TYPENAME_typename
 
-#  if (defined(__cpp_concepts) && _CCCL_STD_VER >= 2020) || defined(_CCCL_DOXYGEN_INVOKED)
+#  if !defined(_CCCL_NO_CONCEPTS) || defined(_CCCL_DOXYGEN_INVOKED)
 
 #    define _CCCL_CONCEPT concept
 
@@ -167,7 +168,7 @@ namespace __cccl_unqualified_cuda_std = _CUDA_VSTD; // NOLINT(misc-unused-alias-
 
 #    define _CCCL_FRAGMENT(_NAME, ...) _NAME<__VA_ARGS__>
 
-#  else
+#  else // ^^^ !_CCCL_NO_CONCEPTS ^^^ / vvv _CCCL_NO_CONCEPTS vvv
 
 #    define _CCCL_CONCEPT _CCCL_INLINE_VAR constexpr bool
 
@@ -207,7 +208,7 @@ namespace __cccl_unqualified_cuda_std = _CUDA_VSTD; // NOLINT(misc-unused-alias-
 #    define _CCCL_FRAGMENT(_NAME, ...) \
       (1u == sizeof(_NAME##_CCCL_CONCEPT_FRAGMENT_(static_cast<::__cccl_tag<__VA_ARGS__>*>(nullptr), nullptr)))
 
-#  endif
+#  endif // ^^^ _CCCL_NO_CONCEPTS ^^^
 
 ////////////////////////////////////////////////////////////////////////////////
 // _CCCL_REQUIRES_EXPR
@@ -220,10 +221,10 @@ namespace __cccl_unqualified_cuda_std = _CUDA_VSTD; // NOLINT(misc-unused-alias-
 //     );
 //
 // Can only be used as the last requirement in a concept definition.
-#  if defined(__cpp_concepts) && _CCCL_STD_VER >= 2020 || defined(_CCCL_DOXYGEN_INVOKED)
+#  if !defined(_CCCL_NO_CONCEPTS) || defined(_CCCL_DOXYGEN_INVOKED)
 #    define _CCCL_REQUIRES_EXPR(_TY, ...) requires(__VA_ARGS__) _CCCL_REQUIRES_EXPR_2
 #    define _CCCL_REQUIRES_EXPR_2(...)    {_CCCL_PP_FOR_EACH(_CCCL_CONCEPT_FRAGMENT_REQS_M, __VA_ARGS__)}
-#  else
+#  else // ^^^ !_CCCL_NO_CONCEPTS ^^^ / vvv _CCCL_NO_CONCEPTS vvv
 #    define _CCCL_REQUIRES_EXPR_TPARAM_PROBE_variadic _CCCL_PP_PROBE(~)
 #    define _CCCL_REQUIRES_EXPR_TPARAM_variadic
 
@@ -268,8 +269,8 @@ namespace __cccl_unqualified_cuda_std = _CUDA_VSTD; // NOLINT(misc-unused-alias-
         return false;                                                                                     \
       }                                                                                                   \
       }
-#  endif
+#  endif // ^^^ _CCCL_NO_CONCEPTS ^^^
 
-#endif // _CCCL_STD_VER >= 2014
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES ^^^
 
 #endif //_CUDA___CONCEPTS
diff --git a/libcudacxx/include/cuda/std/__concepts/constructible.h b/libcudacxx/include/cuda/std/__concepts/constructible.h
@@ -28,7 +28,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concept.constructible]
 template <class _Tp, class... _Args>
@@ -52,7 +52,7 @@ concept copy_constructible =
   && constructible_from<_Tp, const _Tp&> && convertible_to<const _Tp&, _Tp> && constructible_from<_Tp, const _Tp>
   && convertible_to<const _Tp, _Tp>;
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Tp, class... _Args>
 _CCCL_CONCEPT_FRAGMENT(__constructible_from_,
@@ -96,7 +96,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Tp>
 _CCCL_CONCEPT copy_constructible = _CCCL_FRAGMENT(__copy_constructible_, _Tp);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/convertible_to.h b/libcudacxx/include/cuda/std/__concepts/convertible_to.h
@@ -28,12 +28,12 @@ _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
 // [concept.convertible]
 
-#if _CCCL_STD_VER >= 2020
+#if !defined(_CCCL_NO_CONCEPTS)
 
 template <class _From, class _To>
 concept convertible_to = is_convertible_v<_From, _To> && requires { static_cast<_To>(_CUDA_VSTD::declval<_From>()); };
 
-#elif _CCCL_STD_VER >= 2014 // ^^^ C++20 ^^^ / vvv C++14/17 vvv
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 #  if _CCCL_COMPILER(MSVC)
 _CCCL_NV_DIAG_SUPPRESS(1211) // nonstandard cast to array type ignored
@@ -60,7 +60,7 @@ _CCCL_NV_DIAG_DEFAULT(1211) // nonstandard cast to array type ignored
 #  endif // _CCCL_COMPILER(MSVC)
 _CCCL_NV_DIAG_DEFAULT(171) // invalid type conversion, e.g. [with _From=int **, _To=const int *const *]
 
-#endif // _CCCL_STD_VER >= 2014
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES ^^^
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/copyable.h b/libcudacxx/include/cuda/std/__concepts/copyable.h
@@ -27,15 +27,15 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concepts.object]
 
 template <class _Tp>
 concept copyable = copy_constructible<_Tp> && movable<_Tp> && assignable_from<_Tp&, _Tp&>
                 && assignable_from<_Tp&, const _Tp&> && assignable_from<_Tp&, const _Tp>;
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Tp>
 _CCCL_CONCEPT_FRAGMENT(
@@ -49,7 +49,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Tp>
 _CCCL_CONCEPT copyable = _CCCL_FRAGMENT(__copyable_, _Tp);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/derived_from.h b/libcudacxx/include/cuda/std/__concepts/derived_from.h
@@ -27,14 +27,14 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2017
+#if !defined(_CCCL_NO_CONCEPTS)
 
 // [concept.derived]
 
 template <class _Dp, class _Bp>
 concept derived_from = is_base_of_v<_Bp, _Dp> && is_convertible_v<const volatile _Dp*, const volatile _Bp*>;
 
-#elif _CCCL_STD_VER > 2011
+#elif !defined(_CCCL_NO_VARIABLE_TEMPLATES) // ^^^ !_CCCL_NO_CONCEPTS ^^^
 
 template <class _Dp, class _Bp>
 _CCCL_CONCEPT_FRAGMENT(
@@ -46,7 +46,7 @@ _CCCL_CONCEPT_FRAGMENT(
 template <class _Dp, class _Bp>
 _CCCL_CONCEPT derived_from = _CCCL_FRAGMENT(__derived_from_, _Dp, _Bp);
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/destructible.h b/libcudacxx/include/cuda/std/__concepts/destructible.h
@@ -30,7 +30,7 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2011
+#if !defined(_CCCL_NO_VARIABLE_TEMPLATES)
 
 #  if _CCCL_COMPILER(MSVC)
 
@@ -69,7 +69,7 @@ _CCCL_CONCEPT destructible = __destructible<_Tp>;
 
 #  endif // !_CCCL_COMPILER(MSVC)
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD
 

diff --git a/libcudacxx/include/cuda/std/__concepts/different_from.h b/libcudacxx/include/cuda/std/__concepts/different_from.h
@@ -26,12 +26,12 @@
 
 _LIBCUDACXX_BEGIN_NAMESPACE_STD
 
-#if _CCCL_STD_VER > 2011
+#if !defined(_CCCL_NO_VARIABLE_TEMPLATES)
 
 template <class _Tp, class _Up>
 _CCCL_CONCEPT __different_from = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>;
 
-#endif // _CCCL_STD_VER > 2011
+#endif // ^^^ !_CCCL_NO_VARIABLE_TEMPLATES
 
 _LIBCUDACXX_END_NAMESPACE_STD