System.IO.Pipes

 namespace System.IO.Pipes {
     public abstract class PipeStream : Stream {
+        public override int Read(Span<byte> buffer);
+        public override ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default(CancellationToken));
+        public override void Write(ReadOnlySpan<byte> buffer);
+        public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default(CancellationToken));
     }
 }