From 7c52a62aa559c9363f71ed245ad73166109f81b8 Mon Sep 17 00:00:00 2001
From: smdn <smdn@smdn.jp>
Date: Sat, 5 Feb 2022 01:39:15 +0900
Subject: [PATCH] use Stream.ReadAsync(Memory) if available

---
 src/Smdn.Fundamental.Stream/Smdn.IO/StreamExtensions.cs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Smdn.Fundamental.Stream/Smdn.IO/StreamExtensions.cs b/src/Smdn.Fundamental.Stream/Smdn.IO/StreamExtensions.cs
index 9ba99a492..68199c185 100644
--- a/src/Smdn.Fundamental.Stream/Smdn.IO/StreamExtensions.cs
+++ b/src/Smdn.Fundamental.Stream/Smdn.IO/StreamExtensions.cs
@@ -68,7 +68,13 @@ async Task CopyToAsyncCore()
       var buffer = new byte[bufferSize]; // TODO: array pool
 
       for (; ; ) {
-        var read = await stream.ReadAsync(buffer, 0, bufferSize, cancellationToken).ConfigureAwait(false);
+        var read =
+#if SYSTEM_IO_STREAM_READASYNC_MEMORY_OF_BYTE
+          await stream.ReadAsync(buffer.AsMemory(0, bufferSize), cancellationToken)
+#else
+          await stream.ReadAsync(buffer, 0, bufferSize, cancellationToken)
+#endif
+          .ConfigureAwait(false);
 
         if (read <= 0)
           break;