[UNTESTED] Basic queue and fan-in fabric implementation without full template generalization

include/weaver/atomic.h

@@ -0,0 +1,88 @@
+#ifndef THWEAVER_ATOMIC_H
+#define THWEAVER_ATOMIC_H
+
+#include <cstdint>
+#include <concepts>
+#include <limits>
+#include <type_traits>
+
+template <typename T>
+concept Additive = std::is_integral_v<T> && !std::is_same_v<T, bool>;
+
+template <typename A, typename T>
+concept AtomicAdditive =
+requires(A a, T v) {
+        {
+                a.load()
+        }
+        -> std::same_as<T>;
+        {
+                a.store(v)
+        };
+        {
+                a.fetch_add(v)
+        }
+        -> std::same_as<T>;
+        {
+                a.fetch_sub(v)
+        }
+        -> std::same_as<T>;
+};
+
+template <typename T>
+concept Bitwise =
+        (std::is_integral_v<T> || std::is_enum_v<T>) &&
+        !std::is_same_v<T, bool>;
+
+template <typename A, typename T>
+concept AtomicBitwise =
+requires(A a, T v) {
+        {
+                a.load()
+        }
+        -> std::same_as<T>;
+        {
+                a.store(v)
+        };
+        {
+                a.fetch_or(v)
+        }
+        -> std::same_as<T>;
+        {
+                a.fetch_and(v)
+        }
+        -> std::same_as<T>;
+        {
+                a.fetch_xor(v)
+        }
+        -> std::same_as<T>;
+};
+
+// Uses the full bitmap
+template<typename Atomic, typename T, uint32_t NumBits, typename Index = uint32_t>
+requires Bitwise<T> && AtomicBitwise<Atomic, T> &&
+Additive<Index> && std::is_unsigned_v<Index>
+class AtomicBitmap {
+public:
+        static_assert(NumBits <= std::numeric_limits<T>::digits);
+
+        AtomicBitmap() noexcept
+                : bits(T {}), rotation(0) {}
+
+        void reset(const T &bits, const Index rotation) noexcept;
+
+        bool get_bit(const Index n) const noexcept;
+        void set_bit(const Index n) noexcept;
+        void clear_bit(const Index n) noexcept;
+
+        void rotate(const Index n) noexcept;
+        Index get_rotation() const noexcept;
+
+        Index get_low_bit() const noexcept;
+        Index rotate_to_low_bit(const Index offset = 0) noexcept;
+private:
+        Atomic bits;
+        Index rotation;
+};
+
+#endif