async: Add source/sink concepts.

1 files changed, 42 insertions, 0 deletions

diff --git a/async/concepts.h b/async/concepts.h
new file mode 100644
index 0000000..41f878a
--- /dev/null
+++ b/async/concepts.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <concepts>
+#include <cstdint>
+#include <span>
+
+template <typename T, typename U = void>
+concept async_awaitable = requires(T a)
+{
+    // TODO: await_ready and await_suspend
+    { a.await_resume() } -> std::same_as<U>;
+};
+
+template <typename T, typename U>
+concept async_source = requires(T a)
+{
+    { a.async_get() } -> async_awaitable<U>;
+};
+
+template <typename T, typename U>
+concept async_sink = requires(T a, U v)
+{
+    { a.async_put(v) } -> async_awaitable<>;
+};
+
+template <typename T>
+concept async_byte_source = async_source<T, uint8_t>;
+
+template <typename T>
+concept async_byte_sink = async_sink<T, uint8_t>;
+
+template <typename T>
+concept async_packet_source = requires(T a, std::span<uint8_t> buf)
+{
+    { a.async_read(buf) } -> async_awaitable<std::span<uint8_t>>;
+};
+
+template <typename T>
+concept async_packet_sink = requires(T a, std::span<uint8_t> buf)
+{
+    { a.async_write(buf) } -> async_awaitable<>;
+};