From 4d655cdd198d7cf7798f6831b1f641d832d3de7c Mon Sep 17 00:00:00 2001
From: Alex Barney <thealexbarney@gmail.com>
Date: Mon, 25 Feb 2019 12:37:30 -0600
Subject: [PATCH] Use the Unsafe class in RomFsDictionary

---
 src/LibHac/IO/RomFs/RomFsDictionary.cs | 13 ++++++-------
 src/LibHac/LibHac.csproj               |  6 +++++-
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/LibHac/IO/RomFs/RomFsDictionary.cs b/src/LibHac/IO/RomFs/RomFsDictionary.cs
index 9c6a3cfd..6326ee4b 100644
--- a/src/LibHac/IO/RomFs/RomFsDictionary.cs
+++ b/src/LibHac/IO/RomFs/RomFsDictionary.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace LibHac.IO.RomFs
@@ -13,8 +14,7 @@ namespace LibHac.IO.RomFs
         private int[] Buckets { get; set; }
         private byte[] Entries { get; set; }
 
-        // Hack around not being able to get the size of generic structures
-        private readonly int _sizeOfEntry = 12 + Marshal.SizeOf<T>();
+        private readonly int _sizeOfEntry = Unsafe.SizeOf<RomFsEntry>();
 
         public RomFsDictionary(IStorage bucketStorage, IStorage entryStorage)
         {
@@ -68,13 +68,12 @@ namespace LibHac.IO.RomFs
 
         public ref T GetValueReference(int offset)
         {
-            ref RomFsEntry entry = ref MemoryMarshal.Cast<byte, RomFsEntry>(Entries.AsSpan(offset))[0];
-            return ref entry.Value;
+            return ref Unsafe.As<byte, RomFsEntry>(ref Entries[offset]).Value;
         }
 
         public ref T GetValueReference(int offset, out Span<byte> name)
         {
-            ref RomFsEntry entry = ref MemoryMarshal.Cast<byte, RomFsEntry>(Entries.AsSpan(offset))[0];
+            ref RomFsEntry entry = ref Unsafe.As<byte, RomFsEntry>(ref Entries[offset]);
 
             name = Entries.AsSpan(offset + _sizeOfEntry, entry.KeyLength);
             return ref entry.Value;
@@ -249,7 +248,7 @@ namespace LibHac.IO.RomFs
 
         private ref RomFsEntry GetEntryReference(int offset, out Span<byte> name)
         {
-            ref RomFsEntry entry = ref MemoryMarshal.Cast<byte, RomFsEntry>(Entries.AsSpan(offset))[0];
+            ref RomFsEntry entry = ref Unsafe.As<byte, RomFsEntry>(ref Entries[offset]);
 
             name = Entries.AsSpan(offset + _sizeOfEntry, entry.KeyLength);
             return ref entry;
@@ -257,7 +256,7 @@ namespace LibHac.IO.RomFs
 
         private ref RomFsEntry GetEntryReference(int offset, out Span<byte> name, int nameLength)
         {
-            ref RomFsEntry entry = ref MemoryMarshal.Cast<byte, RomFsEntry>(Entries.AsSpan(offset))[0];
+            ref RomFsEntry entry = ref Unsafe.As<byte, RomFsEntry>(ref Entries[offset]);
 
             name = Entries.AsSpan(offset + _sizeOfEntry, nameLength);
             return ref entry;
diff --git a/src/LibHac/LibHac.csproj b/src/LibHac/LibHac.csproj
index 29038b06..8f04d210 100644
--- a/src/LibHac/LibHac.csproj
+++ b/src/LibHac/LibHac.csproj
@@ -35,8 +35,12 @@
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net46' ">
     <PackageReference Include="System.Numerics.Vectors" Version="4.5.0" />
-    <PackageReference Include="System.Memory" Version="4.5.1" />
+    <PackageReference Include="System.Memory" Version="4.5.2" />
     <PackageReference Include="System.Buffers" Version="4.5.0" />
   </ItemGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' ">
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="4.5.2" />
+  </ItemGroup>
+
 </Project>