Create atomic headers

include/preview/__atomic/atomic.h

@@ -0,0 +1,57 @@
+//
+// Created by yonggyulee on 2024. 7. 18.
+//
+
+#ifndef PREVIEW_ATOMIC_ATOMIC_H_
+#define PREVIEW_ATOMIC_ATOMIC_H_
+
+#include <type_traits>
+
+#include "preview/__atomic/detail/atomic_floating_point.h"
+#include "preview/__atomic/detail/atomic_generic.h"
+#include "preview/__atomic/detail/atomic_integral.h"
+#include "preview/__atomic/detail/atomic_pointer.h"
+#include "preview/__type_traits/disjunction.h"
+#include "preview/__type_traits/conditional.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T, bool = disjunction<std::is_integral<T>, std::is_floating_point<T>>::value>
+struct atomic_difference_type {};
+template<typename T>
+struct atomic_difference_type<T, true> { using type = T; };
+
+template<typename T>
+using atomic_base_t = conditional_t<
+    std::is_integral<T>,       atomic_integral<T>,
+    std::is_floating_point<T>, atomic_floating_point<T>,
+    std::is_pointer<T>,        atomic_pointer<T>,
+    atomic_generic<T>
+>;
+
+} // namespace detail
+
+template<typename T>
+class atomic : public detail::atomic_base_t<T> {
+  using base = detail::atomic_base_t<T>;
+public:
+  using base::base;
+
+  T operator=(T desired) noexcept {
+    this->store(desired);
+    return desired;
+  }
+
+  T operator=(T desired) volatile noexcept {
+    this->store(desired);
+    return desired;
+  }
+
+  atomic<T>& operator=(const atomic<T>& other) = delete;
+  atomic<T>& operator=(const atomic<T>& other) volatile = delete;
+};
+
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_ATOMIC_H_

include/preview/__atomic/atomic_notify_all.h

@@ -0,0 +1,12 @@
+//
+// Created by yonggyulee on 2024. 7. 19.
+//
+
+#ifndef PREVIEW_ATOMIC_ATOMIC_NOTIFY_ALL_H_
+#define PREVIEW_ATOMIC_ATOMIC_NOTIFY_ALL_H_
+
+namespace preview {
+
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_ATOMIC_NOTIFY_ALL_H_

include/preview/__atomic/atomic_notify_one.h

@@ -0,0 +1,12 @@
+//
+// Created by yonggyulee on 2024. 7. 19.
+//
+
+#ifndef PREVIEW_ATOMIC_ATOMIC_NOTIFY_ONE_H_
+#define PREVIEW_ATOMIC_ATOMIC_NOTIFY_ONE_H_
+
+namespace preview {
+
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_ATOMIC_NOTIFY_ONE_H_

include/preview/__atomic/atomic_wait.h

@@ -0,0 +1,43 @@
+//
+// Created by yonggyulee on 2024. 7. 19.
+//
+
+#ifndef PREVIEW_ATOMIC_ATOMIC_WAIT_H_
+#define PREVIEW_ATOMIC_ATOMIC_WAIT_H_
+
+#include <atomic>
+#include <cassert>
+
+#include "preview/__atomic/atomic.h"
+
+namespace preview {
+
+template<typename T>
+void atomic_wait(const atomic<T>* object, typename atomic<T>::value_type old) {
+  object->wait(old);
+}
+
+template<typename T>
+void atomic_wait(const volatile atomic<T>* object, typename atomic<T>::value_type old) {
+  object->wait(old);
+}
+
+template<typename T>
+void atomic_wait_explicit(const atomic<T>* object, typename atomic<T>::value_type old, std::memory_order order) {
+  assert(order != std::memory_order_relaxed);
+  assert(order != std::memory_order_acq_rel);
+
+  object->wait(old, order);
+}
+
+template<typename T>
+void atomic_wait_explicit(const volatile atomic<T>* object, typename atomic<T>::value_type old, std::memory_order order) {
+  assert(order != std::memory_order_relaxed);
+  assert(order != std::memory_order_acq_rel);
+
+  object->wait(old, order);
+}
+
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_ATOMIC_WAIT_H_

include/preview/__atomic/detail/atomic_floating_point.h

@@ -0,0 +1,24 @@
+//
+// Created by yonggyulee on 2024. 9. 2.
+//
+
+#ifndef PREVIEW_ATOMIC_DETAIL_ATOMIC_FLOATING_POINT_H_
+#define PREVIEW_ATOMIC_DETAIL_ATOMIC_FLOATING_POINT_H_
+
+#include "preview/__atomic/detail/cxx20_atomic_base.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T>
+struct atomic_floating_point : public cxx20_atomic_base<T> {
+  using value_type      = T;
+  using difference_type = value_type;
+
+  using cxx20_atomic_base<T>::cxx20_atomic_base;
+};
+
+} // namespace detail
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_DETAIL_ATOMIC_FLOATING_POINT_H_

include/preview/__atomic/detail/atomic_generic.h

@@ -0,0 +1,19 @@
+//
+// Created by yonggyulee on 2024. 9. 2.
+//
+
+#ifndef PREVIEW_ATOMIC_DETAIL_ATOMIC_GENERIC_H_
+#define PREVIEW_ATOMIC_DETAIL_ATOMIC_GENERIC_H_
+
+#include "preview/__atomic/detail/cxx20_atomic_base.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T>
+struct atomic_generic : cxx20_atomic_base<T> {};
+
+} // namespace detail
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_DETAIL_ATOMIC_GENERIC_H_

include/preview/__atomic/detail/atomic_integral.h

@@ -0,0 +1,27 @@
+//
+// Created by yonggyulee on 2024. 9. 2.
+//
+
+#ifndef PREVIEW_ATOMIC_DETAIL_ATOMIC_INTEGRAL_H_
+#define PREVIEW_ATOMIC_DETAIL_ATOMIC_INTEGRAL_H_
+
+#include "preview/__atomic/detail/cxx20_atomic_base.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T>
+class atomic_integral : public cxx20_atomic_base<T> {
+ public:
+  using cxx20_atomic_base<T>::cxx20_atomic_base;
+
+  // TODO: Implement fetch_max
+//  T fetch_max(T operand, std::memory_order order = std::memory_order_seq_cst) noexcept {}
+//  T fetch_max(T operand, std::memory_order order = std::memory_order_seq_cst) volatile noexcept {}
+
+};
+
+} // namespace detail
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_DETAIL_ATOMIC_INTEGRAL_H_

include/preview/__atomic/detail/atomic_pointer.h

@@ -0,0 +1,24 @@
+//
+// Created by yonggyulee on 2024. 9. 2.
+//
+
+#ifndef PREVIEW_ATOMIC_DETAIL_ATOMIC_POINTER_H_
+#define PREVIEW_ATOMIC_DETAIL_ATOMIC_POINTER_H_
+
+#include "preview/__atomic/detail/cxx20_atomic_base.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T>
+struct atomic_pointer : public cxx20_atomic_base<T> {
+
+  // TODO: Implement fetch_max
+//  T fetch_max(T operand, std::memory_order order = std::memory_order_seq_cst) noexcept {}
+//  T fetch_max(T operand, std::memory_order order = std::memory_order_seq_cst) volatile noexcept {}
+};
+
+} // namespace detail
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_DETAIL_ATOMIC_POINTER_H_

include/preview/__atomic/detail/cxx20_atomic_base.h

@@ -0,0 +1,67 @@
+//
+// Created by yonggyulee on 2024. 9. 2.
+//
+
+#ifndef PREVIEW_ATOMIC_DETAIL_ATOMIC_BASE_H_
+#define PREVIEW_ATOMIC_DETAIL_ATOMIC_BASE_H_
+
+#include <atomic>
+#include <type_traits>
+
+#include "preview/config.h"
+
+#if PREVIEW_USE_BOOST_ATOMIC
+#include "boost/atomic.hpp"
+#endif
+
+#include "preview/__type_traits/conjunction.h"
+#include "preview/__type_traits/has_typename_difference_type.h"
+#include "preview/__type_traits/void_t.h"
+
+namespace preview {
+namespace detail {
+
+template<typename T, typename = void>
+struct has_member_function_wait : std::false_type {};
+template<typename T>
+struct has_member_function_wait<T, void_t<decltype(std::declval<T>().wait(std::declval<T>(), std::declval<std::memory_order>()))>> : std::true_type {};
+
+template<typename T, typename = void>
+struct has_member_function_notify_one : std::false_type {};
+template<typename T>
+struct has_member_function_notify_one<T, void_t<decltype(std::declval<T>().notify_one())>> : std::true_type {};
+
+template<typename T, typename = void>
+struct has_member_function_notify_all : std::false_type {};
+template<typename T>
+struct has_member_function_notify_all<T, void_t<decltype(std::declval<T>().notify_all())>> : std::true_type {};
+
+template<typename T>
+struct has_wait_and_notify : conjunction<
+    has_member_function_wait<T>,
+    has_member_function_notify_one<T>,
+    has_member_function_notify_all<T>
+> {};
+
+template<typename T>
+struct is_cxx20_atomic : conjunction<
+    has_wait_and_notify<T>,
+    has_typename_difference_type<T>
+> {};
+
+template<typename T>
+using cxx20_atomic_base =
+#if PREVIEW_USE_BOOST_ATOMIC
+    boost::atomic<T>;
+#else
+    std::atomic<T>;
+    static_assert(is_cxx20_atomic<std::atomic<int>>::value,
+        "std::atomic<T> does not conform C++20 standard. Set PREVIEW_USE_BOOST_ATOMIC to 1");
+#endif
+
+
+
+} // namespace detail
+} // namespace preview
+
+#endif // PREVIEW_ATOMIC_DETAIL_ATOMIC_BASE_H_

include/preview/atomic.h

@@ -0,0 +1,13 @@
+//
+// Created by yonggyulee on 2024. 7. 18.
+//
+
+#ifndef PREVIEW_ATOMIC_H_
+#define PREVIEW_ATOMIC_H_
+
+#include "preview/__atomic/atomic.h"
+#include "preview/__atomic/atomic_notify_all.h"
+#include "preview/__atomic/atomic_notify_one.h"
+#include "preview/__atomic/atomic_wait.h"
+
+#endif // PREVIEW_ATOMIC_H_

include/preview/cmake_config.h.in

@@ -4,22 +4,33 @@
 
 #include "preview/core.h"
 
-# if PREVIEW_CXX_VERSION >= 20 && \
-         (!defined(__clang_major__) || (defined(__clang_major__) && __clang_major__ > 11)) && \
-         (!defined(PREVIEW_NDK_VERSION_MAJOR) || PREVIEW_NDK_VERSION_MAJOR >= 26)
-#   define PREVIEW_CONFORM_CXX20_STANDARD 1
-# else
-#   define PREVIEW_CONFORM_CXX20_STANDARD 0
-# endif
+#if PREVIEW_CXX_VERSION >= 20 && \
+        (!defined(__clang_major__) || (defined(__clang_major__) && __clang_major__ > 11)) && \
+        (!defined(PREVIEW_NDK_VERSION_MAJOR) || PREVIEW_NDK_VERSION_MAJOR >= 26)
+#  define PREVIEW_CONFORM_CXX20_STANDARD 1
+#else
+#  define PREVIEW_CONFORM_CXX20_STANDARD 0
+#endif
 
 #ifdef PREVIEW_CMAKE_CONFIG
+#  cmakedefine PREVIEW_CONFIGURED_CXX_VERSION ${CMAKE_CXX_STANDARD}
+#  if PREVIEW_CONFIGURED_CXX_VERSION != PREVIEW_CXX_VERSION
+#    warning "STL-Preview is configured for different C++ standard version"
+#  else
+#    define PREVIEW_USE_CMAKE_CONFIG
+#  endif
+#endif
+
+#ifdef PREVIEW_USE_CMAKE_CONFIG
 
 #cmakedefine01 PREVIEW_HAVE_BUILTIN_BIT_CAST
 #cmakedefine01 PREVIEW_HAVE_BUILTIN_CONSTEXPR_ADDRESSOF
 
 #cmakedefine01 PREVIEW_HAVE_STRING_VIEW
 #cmakedefine01 PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG
 
+#cmakedefine01 PREVIEW_USE_BOOST_ATOMIC
+
 #else
 
 #define PREVIEW_HAVE_BUILTIN_BIT_CAST            PREVIEW_CONFORM_CXX20_STANDARD
@@ -28,4 +39,8 @@
 #define PREVIEW_HAVE_CONTIGUOUS_ITERATOR_TAG PREVIEW_CONFORM_CXX20_STANDARD
 #define PREVIEW_HAVE_STRING_VIEW             (PREVIEW_CXX_VERSION >= 17)
 
+#ifndef PREVIEW_USE_BOOST_ATOMIC
+#  define PREVIEW_USE_BOOST_ATOMIC (PREVIEW_CXX_VERSION < 20)
+#endif
+
 #endif