simplify copying and comparing Node by using ReadOnlySpan<T>

Author: smdn

src/Smdn.Fundamental.Uuid/Smdn.Formats.UniversallyUniqueIdentifiers/Node.IComparable.cs

@@ -23,6 +23,9 @@ public int CompareTo(object obj)
     };
 
   public int CompareTo(Node other)
+#if NODE_READONLYSPAN
+    => NodeSpan.SequenceCompareTo(other.NodeSpan);
+#else
   {
     int ret;
 
@@ -41,4 +44,5 @@ public int CompareTo(Node other)
 
     return 0;
   }
+#endif
 }

src/Smdn.Fundamental.Uuid/Smdn.Formats.UniversallyUniqueIdentifiers/Node.IEquatable.cs

@@ -20,10 +20,14 @@ public override bool Equals(object obj)
 
   public bool Equals(Node other)
     =>
+#if NODE_READONLYSPAN
+      NodeSpan.SequenceEqual(other.NodeSpan);
+#else
       N0 == other.N0 &&
       N1 == other.N1 &&
       N2 == other.N2 &&
       N3 == other.N3 &&
       N4 == other.N4 &&
       N5 == other.N5;
+#endif
 }

src/Smdn.Fundamental.Uuid/Smdn.Formats.UniversallyUniqueIdentifiers/Node.cs

@@ -5,11 +5,12 @@
 #if SYSTEM_NET_NETWORKINFORMATION_PHYSICALADDRESS
 using System.Net.NetworkInformation;
 #endif
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace Smdn.Formats.UniversallyUniqueIdentifiers;
 
-[System.Runtime.CompilerServices.TypeForwardedFrom("Smdn, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null")]
+[TypeForwardedFrom("Smdn, Version=3.0.0.0, Culture=neutral, PublicKeyToken=null")]
 [StructLayout(LayoutKind.Sequential, Pack = 1, Size = 6)]
 public readonly partial struct Node : IFormattable {
   private const int SizeOfSelf = 6;
@@ -32,6 +33,10 @@ public static Node CreateRandom()
   internal readonly byte N4;
   internal readonly byte N5;
 
+#if NODE_READONLYSPAN
+  internal ReadOnlySpan<byte> NodeSpan => MemoryMarshal.CreateReadOnlySpan(ref Unsafe.AsRef(in N0), SizeOfSelf);
+#endif
+
 #if SYSTEM_NET_NETWORKINFORMATION_PHYSICALADDRESS
   public Node(PhysicalAddress physicalAddress)
     : this((physicalAddress ?? throw new ArgumentNullException(nameof(physicalAddress))).GetAddressBytes())
@@ -99,6 +104,9 @@ public void WriteBytes(Span<byte> destination)
   }
 
   public bool TryWriteBytes(Span<byte> destination)
+#if NODE_READONLYSPAN
+    => NodeSpan.TryCopyTo(destination);
+#else
   {
     if (destination.Length < SizeOfSelf)
       return false;
@@ -112,6 +120,7 @@ public bool TryWriteBytes(Span<byte> destination)
 
     return true;
   }
+#endif
 
   public static Node Parse(string s)
     => TryParse(s ?? throw new ArgumentNullException(nameof(s)), out var result)

src/Smdn.Fundamental.Uuid/Smdn.Fundamental.Uuid.csproj

@@ -21,6 +21,7 @@ SPDX-License-Identifier: MIT
   <ItemGroup>
     <ProjectReference VersionRange="[3.0.2,4.0.0)" Include="..\Smdn.Fundamental.Exception\Smdn.Fundamental.Exception.csproj" />
     <PackageReference Include="System.Memory" Version="4.5.4" Condition="$(TargetFramework.StartsWith('net4')) or $(TargetFramework.StartsWith('netstandard1')) or $(TargetFramework.StartsWith('netstandard2.0'))" />
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" Condition="($(TargetFramework.StartsWith('net46')) and '$(TargetFramework)' != 'net46') or $(TargetFramework.StartsWith('netstandard2'))" />
     <PackageReference Include="System.ValueTuple" Version="4.5.0" Condition="$(TargetFramework.StartsWith('net45')) or $(TargetFramework.StartsWith('net46')) or $(TargetFramework.StartsWith('netstandard1'))" />
     <PackageReference Include="Microsoft.Bcl.HashCode" Version="1.1.1" Condition="($(TargetFramework.StartsWith('net46')) and '$(TargetFramework)' != 'net46') or $(TargetFramework.StartsWith('netstandard2.0'))" />
   </ItemGroup>
@@ -33,6 +34,21 @@ SPDX-License-Identifier: MIT
         $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNETCOREAPP2_1_OR_GREATER\b')) Or
         $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNET5_0_OR_GREATER\b'))
       ">$(DefineConstants);SYSTEM_HASHCODE</DefineConstants>
+      <DefineConstants Condition="
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNETSTANDARD2_1_OR_GREATER\b')) Or
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNETCOREAPP2_1_OR_GREATER\b')) Or
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNET5_0_OR_GREATER\b'))
+      ">$(DefineConstants);SYSTEM_RUNTIME_INTEROPSERVICES_MEMORYMARSHAL_CREATEREADONLYSPAN</DefineConstants>
+      <DefineConstants Condition="
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNET461_OR_GREATER\b')) Or
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNETSTANDARD2_1_OR_GREATER\b')) Or
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNETCOREAPP2_0_OR_GREATER\b')) Or
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bNET5_0_OR_GREATER\b'))
+      ">$(DefineConstants);SYSTEM_RUNTIME_COMPILERSERVICES_UNSAFE_ASREF</DefineConstants>
+      <DefineConstants Condition="
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bSYSTEM_RUNTIME_INTEROPSERVICES_MEMORYMARSHAL_CREATEREADONLYSPAN\b')) And
+        $([System.Text.RegularExpressions.Regex]::IsMatch('$(DefineConstants)', '\bSYSTEM_RUNTIME_COMPILERSERVICES_UNSAFE_ASREF\b'))
+      ">$(DefineConstants);NODE_READONLYSPAN</DefineConstants>
     </PropertyGroup>
   </Target>
 </Project>