[MethodImpl(MethodImplOptions.AggressiveOptimization)] // workaround boxing allocations in Tier0: https://github.com/dotnet/runtime/issues/9120
internal static void AwaitUnsafeOnCompleted <TAwaiter>(
ref TAwaiter awaiter, IAsyncStateMachineBox box)
where TAwaiter : ICriticalNotifyCompletion
{
// The null tests here ensure that the jit can optimize away the interface
// tests when TAwaiter is a ref type.
if ((null != (object?)default(TAwaiter)) && (awaiter is ITaskAwaiter))
{
ref TaskAwaiter ta = ref Unsafe.As <TAwaiter, TaskAwaiter>(ref awaiter); // relies on TaskAwaiter/TaskAwaiter<T> having the same layout
TaskAwaiter.UnsafeOnCompletedInternal(ta.m_task, box, continueOnCapturedContext: true);
}