From a77dd5f8549cff80863b79de281d68c1905edab4 Mon Sep 17 00:00:00 2001
From: Andrew Arnott <andrewarnott@gmail.com>
Date: Mon, 24 Feb 2020 16:42:00 -0700
Subject: [PATCH] Fix Sequence<T> to work for managed types T

Fixes #167
---
 src/Nerdbank.Streams.Tests/SequenceTests.cs  | 10 ++++++++++
 src/Nerdbank.Streams/Nerdbank.Streams.csproj |  1 +
 src/Nerdbank.Streams/Sequence`1.cs           |  2 +-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/Nerdbank.Streams.Tests/SequenceTests.cs b/src/Nerdbank.Streams.Tests/SequenceTests.cs
index aa87d365..acc4a19c 100644
--- a/src/Nerdbank.Streams.Tests/SequenceTests.cs
+++ b/src/Nerdbank.Streams.Tests/SequenceTests.cs
@@ -469,6 +469,16 @@ public void Dispose_ClearsAndAllowsReuse()
         Assert.Equal(3, seq.AsReadOnlySequence.Length);
     }
 
+    [Fact]
+    public void SequenceOfManagedType()
+    {
+        var seq = new Sequence<object>();
+        seq.Write(new object[] { new object(), new object() });
+        Assert.Equal(2, seq.Length);
+        Assert.IsType<object>(seq.AsReadOnlySequence.First.Span[0]);
+        Assert.IsType<object>(seq.AsReadOnlySequence.First.Span[1]);
+    }
+
     /// <summary>
     /// Adds a reference to an object in the sequence and returns a weak reference to it.
     /// </summary>
diff --git a/src/Nerdbank.Streams/Nerdbank.Streams.csproj b/src/Nerdbank.Streams/Nerdbank.Streams.csproj
index aa1854bf..a20e5065 100644
--- a/src/Nerdbank.Streams/Nerdbank.Streams.csproj
+++ b/src/Nerdbank.Streams/Nerdbank.Streams.csproj
@@ -21,6 +21,7 @@
     <PackageReference Include="System.Buffers" Version="4.5.0" />
     <PackageReference Include="System.IO.Pipelines" Version="4.5.3" />
     <PackageReference Include="System.Net.WebSockets" Version="4.3.0" />
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.6.0" />
     <PackageReference Include="System.ValueTuple" Version="4.5.0" />
   </ItemGroup>
   <ItemGroup>
diff --git a/src/Nerdbank.Streams/Sequence`1.cs b/src/Nerdbank.Streams/Sequence`1.cs
index 5f0fe8d4..4a5911c1 100644
--- a/src/Nerdbank.Streams/Sequence`1.cs
+++ b/src/Nerdbank.Streams/Sequence`1.cs
@@ -23,7 +23,7 @@ namespace Nerdbank.Streams
     [DebuggerDisplay("{" + nameof(DebuggerDisplay) + ",nq}")]
     public class Sequence<T> : IBufferWriter<T>, IDisposable
     {
-        private static readonly int DefaultLengthFromArrayPool = 1 + (4095 / Marshal.SizeOf<T>());
+        private static readonly int DefaultLengthFromArrayPool = 1 + (4095 / Unsafe.SizeOf<T>());
 
         private readonly Stack<SequenceSegment> segmentPool = new Stack<SequenceSegment>();