Bump version

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 17.8.0 to 17.9.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Changelog](https://github.com/microsoft/vstest/blob/main/docs/releases.md)
- [Commits](https://github.com/microsoft/vstest/compare/v17.8.0...v17.9.0)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/dotnet.yml

@@ -7,6 +7,23 @@ on:
     branches: [ master ]
 
 jobs:
+  net8:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup .NET
+      uses: actions/[email protected]
+      with:
+        dotnet-version: 8.0.x
+    - name: Restore dependencies
+      run: dotnet restore
+    - name: Build
+      run: dotnet build --framework net8.0 --no-restore
+    - name: Test
+      run: dotnet test --framework net8.0 --no-build --verbosity normal
+
   net7:
 
     runs-on: ubuntu-latest
@@ -50,9 +67,7 @@ jobs:
     - name: Setup .NET
       uses: actions/[email protected]
       with:
-        dotnet-version: | 
-            5.0.x
-            6.0.x
+        dotnet-version: 5.0.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build

AssetRipper.Primitives.Benckmarks/AssetRipper.Primitives.Benckmarks.csproj

@@ -1,15 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-	<PropertyGroup>
-		<OutputType>Exe</OutputType>
-		<LangVersion>Latest</LangVersion>
-		<TargetFrameworks>net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
-		<ImplicitUsings>enable</ImplicitUsings>
-		<Nullable>enable</Nullable>
-	</PropertyGroup>
-
-	<ItemGroup>
-		<PackageReference Include="BenchmarkDotNet" Version="0.13.11" />
-	</ItemGroup>
-
-</Project>

AssetRipper.Primitives.Benckmarks/Program.cs

@@ -1,11 +0,0 @@
-using BenchmarkDotNet.Running;
-
-namespace AssetRipper.Primitives.Benckmarks;
-
-internal static class Program
-{
-	static void Main()
-	{
-		BenchmarkRunner.Run(typeof(Program).Assembly);
-	}
-}

AssetRipper.Primitives.Benckmarks/YearVersionCheck.cs

@@ -1,46 +0,0 @@
-using BenchmarkDotNet.Attributes;
-using BenchmarkDotNet.Jobs;
-using System.Runtime.CompilerServices;
-
-namespace AssetRipper.Primitives.Benckmarks;
-
-[SimpleJob(RuntimeMoniker.Net80)]
-[RPlotExporter]
-public class YearVersionCheck
-{
-	[Params(4, 5, 6, 7, 2016, 2017, 2018, 2022, 2023, 2024)]
-	public ushort Major;
-
-	[Benchmark]
-	public bool Simple() => Major is >= 2017 and <= 2023;
-
-	[Benchmark]
-	public bool BitsWith2016() => BitComparison(Major);
-
-	[Benchmark]
-	public bool BitsWithout2016() => BitComparison(Major) && Major is not 2016;
-
-	[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-	private static bool BitComparison(uint value)
-	{
-		//This function determines if an unsigned integer
-		//is between 2016 and 2023, inclusive. It does this
-		//by comparing bits of the value with know constants.
-
-		const uint VariableBitMask = 0x7;
-		const uint FixedBitMask = ~VariableBitMask;
-		const uint ExpectedFixedBits = 0x7E0;//2016
-		return (value & FixedBitMask) == ExpectedFixedBits;
-	}
-
-	/* Results:
-	 * Due to the simplicity of the methods being profiled,
-	 * benchmarking was inconclusive. The costs of calling
-	 * these methods are almost neglible.
-	 * 
-	 * Decision:
-	 * For the time being, the library will continue to use
-	 * the simple bounds check. If another option is shown
-	 * to be significantly better, I am open to switching.
-	 */
-}

AssetRipper.Primitives.Tests/AssetRipper.Primitives.Tests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>netframework3.5;netframework4.0;netframework4.8;net5.0;net6.0;net7.0</TargetFrameworks>
+		<TargetFrameworks>net35;net40;net48;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
 		<LangVersion>Latest</LangVersion>
 		<Nullable>enable</Nullable>
 
@@ -9,14 +9,14 @@
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
 		<PackageReference Include="NUnit" Version="3.14.0" />
 		<PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
-		<PackageReference Include="NUnit.Analyzers" Version="3.10.0">
+		<PackageReference Include="NUnit.Analyzers" Version="4.1.0">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
-		<PackageReference Include="coverlet.collector" Version="6.0.0" />
+		<PackageReference Include="coverlet.collector" Version="6.0.2" />
 	</ItemGroup>
 
 	<ItemGroup>

AssetRipper.Primitives.Tests/ComparisonTests.cs

@@ -72,20 +72,4 @@ public class ComparisonTests
 			Assert.That(new UnityVersion(2019, 1, 0, UnityVersionType.Final, 1).LessThanOrEquals(2019, 1, 0));
 		});
 	}
-
-	[TestCase(2017)]
-	[TestCase(2018)]
-	[TestCase(2019)]
-	[TestCase(2020)]
-	[TestCase(2021)]
-	[TestCase(2022)]
-	[TestCase(2023)]
-	public void YearVersioningIsBetweenFiveAndSix(int year)
-	{
-		Assert.Multiple(() =>
-		{
-			Assert.That(new UnityVersion((ushort)year).GreaterThan(5));
-			Assert.That(new UnityVersion((ushort)year).LessThan(6));
-		});
-	}
 }

AssetRipper.Primitives.Tests/ParsingTests.cs

@@ -9,8 +9,13 @@ public class ParsingTests
 	[TestCase("4.2.2f1\n1", 4, 2, 2, UnityVersionType.Final, 1, "\n1", "Custom Unity 4 Version")]
 	[TestCase("2343.4.5f7", 2343, 4, 5, UnityVersionType.Final, 7, null, "Fictitious Future Version")]
 	[TestCase("2019.2.2f1c2\n2", 2019, 2, 2, UnityVersionType.China, 2, "\n2", "Fake Custom Chinese Version")]
+	[TestCase("2019", 2019, 0, 0, UnityVersionType.Final, 1, null, "Major Only")]
 	[TestCase("2019.4", 2019, 4, 0, UnityVersionType.Final, 1, null, "Major Minor Only")]
 	[TestCase("2019.4.3", 2019, 4, 3, UnityVersionType.Final, 1, null, "Major Minor Build Only")]
+	[TestCase("0", 0, 0, 0, UnityVersionType.Alpha, 0, null, "Zero, Major Only")]
+	[TestCase("0.0", 0, 0, 0, UnityVersionType.Alpha, 0, null, "Zero, Major Minor Only")]
+	[TestCase("0.0.0", 0, 0, 0, UnityVersionType.Alpha, 0, null, "Zero, Major Minor Build Only")]
+	[TestCase("0.0.0b2", 0, 0, 0, UnityVersionType.Beta, 2, null, "Zero, Full")]
 	[TestCase("2019.2.2f1-letters", 2019, 2, 2, UnityVersionType.Final, 1, "-letters", "Issue #40 - Appended Custom Characters")]
 	public void UnityVersionParsesCorrectly(string versionString, int major, int minor, int build, UnityVersionType type, int typeNumber, string? customEngine, string name)
 	{
@@ -20,7 +25,7 @@ public class ParsingTests
 		{
 			Assert.That(parsedCustomEngine, Is.EqualTo(customEngine), $"The custom engine boolean is incorrect for '{name}'");
 			Assert.That(parsedVersion, Is.EqualTo(expected), $"The parsed version is incorrect for '{name}'");
-			if (customEngine is not null || typeNumber is not 1)
+			if (customEngine is not null || typeNumber is not 0 and not 1)
 			{
 				Assert.That(parsedVersion.ToString(UnityVersionFormatFlags.Default, parsedCustomEngine ?? ""), Is.EqualTo(versionString));
 			}

AssetRipper.Primitives.Tests/UnityGuidTests.cs

@@ -1,4 +1,4 @@
-#if NET7_0_OR_GREATER
+#if NET5_0_OR_GREATER
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -83,7 +83,7 @@ public class UnityGuidTests
 	{
 		Guid originalGuid = Guid.NewGuid();
 		UnityGuid tobyteArrayGuid = new UnityGuid(originalGuid.ToByteArray());
-		UnityGuid memoryMarshallGuid = new UnityGuid(MemoryMarshal.Cast<Guid, byte>(new ReadOnlySpan<Guid>(in originalGuid)));
+		UnityGuid memoryMarshallGuid = Unsafe.As<Guid, UnityGuid>(ref originalGuid);
 		Assert.That(memoryMarshallGuid, Is.EqualTo(tobyteArrayGuid));
 	}
 }

AssetRipper.Primitives.Tests/Utf8StringTests.cs

@@ -1,4 +1,4 @@
-#if NET7_0_OR_GREATER
+#if NET5_0_OR_GREATER
 namespace AssetRipper.Primitives.Tests;
 
 public class Utf8StringTests

AssetRipper.Primitives.sln

@@ -24,8 +24,6 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AssetRipper.Primitives", "A
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "AssetRipper.Primitives.Tests", "AssetRipper.Primitives.Tests\AssetRipper.Primitives.Tests.csproj", "{545E670D-141B-4F05-9AFD-2F184A59EADC}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AssetRipper.Primitives.Benckmarks", "AssetRipper.Primitives.Benckmarks\AssetRipper.Primitives.Benckmarks.csproj", "{E3DEB571-4EE4-4C89-9005-DB10D9FB561B}"
-EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -40,10 +38,6 @@ Global
 		{545E670D-141B-4F05-9AFD-2F184A59EADC}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{545E670D-141B-4F05-9AFD-2F184A59EADC}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{545E670D-141B-4F05-9AFD-2F184A59EADC}.Release|Any CPU.Build.0 = Release|Any CPU
-		{E3DEB571-4EE4-4C89-9005-DB10D9FB561B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E3DEB571-4EE4-4C89-9005-DB10D9FB561B}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E3DEB571-4EE4-4C89-9005-DB10D9FB561B}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E3DEB571-4EE4-4C89-9005-DB10D9FB561B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

AssetRipper.Primitives/AssetRipper.Primitives.csproj

@@ -1,12 +1,12 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>netframework3.5;netframework4.0;netstandard2.0;net5.0;net6.0;net7.0</TargetFrameworks>
+		<TargetFrameworks>net35;net40;net461;netstandard2.0;net5.0;net6.0;net7.0;net8.0</TargetFrameworks>
 		<LangVersion>Latest</LangVersion>
 		<Nullable>enable</Nullable>
 		<Authors>ds5678</Authors>
 		<Company>AssetRipper</Company>
-		<Version>2.1.0</Version>
+		<Version>3.1.3</Version>
 		<AssemblyVersion>$(Version)</AssemblyVersion>
 		<PackageId>AssetRipper.Primitives</PackageId>
 		<PackageTags>C# assetripper unity unity3d</PackageTags>
@@ -14,26 +14,45 @@
 		<PackageLicenseExpression>MIT</PackageLicenseExpression>
 		<RepositoryType>git</RepositoryType>
 		<PackageProjectUrl>https://github.com/AssetRipper/AssetRipper.Primitives</PackageProjectUrl>
-		<Copyright>Copyright (c) 2022-2023 ds5678</Copyright>
+		<Copyright>Copyright (c) 2022-2024 ds5678</Copyright>
 		<Description>Managed library for primitive types used in AssetRipper.</Description>
 		<GeneratePackageOnBuild>true</GeneratePackageOnBuild>
 		<GenerateDocumentationFile>true</GenerateDocumentationFile>
 		<NoWarn>1591</NoWarn>
 	</PropertyGroup>
 	
-	<PropertyGroup Condition=" '$(TargetFramework)' != 'netframework3.5' and '$(TargetFramework)' != 'netframework4.0' ">
+	<PropertyGroup Condition=" '$(TargetFramework)' != 'net35' and '$(TargetFramework)' != 'net40' ">
 		<IsTrimmable>true</IsTrimmable>
 	</PropertyGroup>
 
+	<PropertyGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
+		<IsAotCompatible>true</IsAotCompatible>
+	</PropertyGroup>
+
 	<ItemGroup>
 		<PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
-		<PackageReference Include="PolySharp" Version="1.14.0">
+		<PackageReference Include="PolySharp" Version="1.14.1">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
 	</ItemGroup>
 
+	<ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'net461'">
+		<PackageReference Include="Microsoft.Bcl.HashCode">
+			<Version>1.1.1</Version>
+		</PackageReference>
+		<PackageReference Include="System.Memory">
+			<Version>4.5.5</Version>
+		</PackageReference>
+	</ItemGroup>
+
+	<ItemGroup Condition="'$(TargetFramework)' == 'net461'">
+		<PackageReference Include="System.ValueTuple">
+			<Version>4.5.0</Version>
+		</PackageReference>
+	</ItemGroup>
+
 </Project>

AssetRipper.Primitives/UnityGuid.cs

@@ -1,21 +1,31 @@
-#if NET7_0_OR_GREATER
+#if NET5_0_OR_GREATER || NETSTANDARD2_0_OR_GREATER || NET461_OR_GREATER
 using System.Buffers.Binary;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Security.Cryptography;
 using System.Text;
-using System.Text.Json.Serialization;
 
 namespace AssetRipper.Primitives;
 
-[JsonConverter(typeof(UnityGuidJsonConverter))]
+#if NET5_0_OR_GREATER
+[System.Text.Json.Serialization.JsonConverter(typeof(UnityGuidJsonConverter))]
+#endif
 public readonly record struct UnityGuid
+#if NET7_0_OR_GREATER
+	: System.Numerics.IEqualityOperators<UnityGuid, UnityGuid, bool>
+#endif
 {
 	public UnityGuid(Guid guid)
 	{
+#if NET5_0_OR_GREATER
 		Span<byte> guidData = stackalloc byte[16];
 		bool success = guid.TryWriteBytes(guidData);
 		Debug.Assert(success);
+#else
+		Span<byte> guidData = guid.ToByteArray();
+#endif
 		ConvertSystemOrUnityBytes(guidData, guidData);
 		Data0 = ReadUInt32LittleEndian(guidData, 0);
 		Data1 = ReadUInt32LittleEndian(guidData, 1);
@@ -44,10 +54,24 @@ public readonly record struct UnityGuid
 		//This is not an acceptable way to convert between Unity and System Guids.
 		//We only do it this way to efficiently get 16 random bytes.
 		//We don't care about official Guid validity because Unity does not care either.
-		Guid guid = Guid.NewGuid();
-		ReadOnlySpan<Guid> guidSpan = new ReadOnlySpan<Guid>(in guid);
-		ReadOnlySpan<byte> byteSpan = MemoryMarshal.AsBytes(guidSpan);
-		return new UnityGuid(byteSpan);
+		if (Unsafe.SizeOf<Guid>() == Unsafe.SizeOf<UnityGuid>())
+		{
+			Guid guid = Guid.NewGuid();
+			return Unsafe.As<Guid, UnityGuid>(ref guid);
+		}
+		else
+		{
+			return ThrowOrReturnDefault();
+		}
+
+		static UnityGuid ThrowOrReturnDefault()
+		{
+#if DEBUG
+			throw new InvalidCastException($"{nameof(UnityGuid)} struct size does not match {nameof(Guid)}.");
+#else
+			return default;
+#endif
+		}
 	}
 
 	public static explicit operator UnityGuid(Guid systemGuid) => new UnityGuid(systemGuid);
@@ -57,7 +81,11 @@ public readonly record struct UnityGuid
 		Span<byte> span = stackalloc byte[16];
 		unityGuid.Write(span);
 		ConvertSystemOrUnityBytes(span, span);
+#if NET5_0_OR_GREATER
 		return new Guid(span);
+#else
+		return new Guid(span.ToArray());
+#endif
 	}
 
 	private void Write(Span<byte> span)
@@ -79,7 +107,16 @@ public readonly record struct UnityGuid
 	{
 		Span<char> span = stackalloc char[32];
 		ToString(span);
-		return new string(span);
+		return CreateString(span);
+
+		static string CreateString(Span<char> span)
+		{
+#if NET5_0_OR_GREATER
+			return new string(span);
+#else
+			return new string(span.ToArray());
+#endif
+		}
 	}
 
 	public void ToString(Span<char> buffer)
@@ -193,15 +230,31 @@ public readonly record struct UnityGuid
 	/// <returns>A stable guid corresponding to the <paramref name="input"/>.</returns>
 	public static UnityGuid Md5Hash(scoped ReadOnlySpan<byte> input)
 	{
-		byte[] hashBytes = MD5.HashData(input);
-		ConvertSystemOrUnityBytes(hashBytes, hashBytes);
-		return new UnityGuid(hashBytes);
+		Span<byte> buffer = stackalloc byte[16];
+		HashData(input, buffer);
+		ConvertSystemOrUnityBytes(buffer, buffer);
+		return new UnityGuid(buffer);
+	}
+
+	private static void HashData(ReadOnlySpan<byte> data, Span<byte> buffer)
+	{
+#if NET5_0_OR_GREATER
+		MD5.HashData(data, buffer);
+#else
+		MD5.Create().ComputeHash(data.ToArray()).AsSpan().CopyTo(buffer);
+#endif
 	}
 
 	public static UnityGuid Md5Hash(scoped ReadOnlySpan<byte> assemblyName, scoped ReadOnlySpan<byte> @namespace, scoped ReadOnlySpan<byte> className)
 	{
 		int length = assemblyName.Length + @namespace.Length + className.Length;
-		Span<byte> input = length < 1024 ? stackalloc byte[length] : GC.AllocateUninitializedArray<byte>(length);
+		Span<byte> input = length < 1024
+			? stackalloc byte[length]
+#if NET5_0_OR_GREATER
+			: GC.AllocateUninitializedArray<byte>(length);
+#else
+			: new byte[length];
+#endif
 		assemblyName.CopyTo(input);
 		@namespace.CopyTo(input.Slice(assemblyName.Length));
 		className.CopyTo(input.Slice(assemblyName.Length + @namespace.Length));

AssetRipper.Primitives/UnityGuidJsonConverter.cs

@@ -1,4 +1,4 @@
-#if NET7_0_OR_GREATER
+#if NET5_0_OR_GREATER
 using System.Text.Json;
 using System.Text.Json.Serialization;
 

AssetRipper.Primitives/UnityVersion.Interfaces.cs

@@ -27,47 +27,7 @@ public readonly partial struct UnityVersion : IEquatable<UnityVersion>, ICompara
 	/// </returns>
 	public int CompareTo(UnityVersion other)
 	{
-		//Unity 6 is sequentially equivalent to Unity 2024 because
-		//they switched to back to the old versioning scheme.
-		const ushort FirstNewVersion = 6;
-
-		if (this == other)
-		{
-			return 0;
-		}
-
-		if (UsesYearNumbering(this))
-		{
-			if (UsesYearNumbering(other))
-			{
-				return CompareByData(this, other);
-			}
-			else
-			{
-				return other.Major < FirstNewVersion ? 1 : -1;
-			}
-		}
-		else
-		{
-			if (UsesYearNumbering(other))
-			{
-				return Major < FirstNewVersion ? -1 : 1;
-			}
-			else
-			{
-				return CompareByData(this, other);
-			}
-		}
-
-		static int CompareByData(UnityVersion x, UnityVersion y)
-		{
-			return x.m_data < y.m_data ? -1 : 1;
-		}
-
-		static bool UsesYearNumbering(UnityVersion version)
-		{
-			return version.Major is >= 2017 and <= 2023;
-		}
+		return m_data.CompareTo(other.m_data);
 	}
 
 	/// <summary>
@@ -90,6 +50,6 @@ public readonly partial struct UnityVersion : IEquatable<UnityVersion>, ICompara
 	/// <inheritdoc/>
 	public override int GetHashCode()
 	{
-		return unchecked(827 + 911 * m_data.GetHashCode());
+		return m_data.GetHashCode();
 	}
 }

AssetRipper.Primitives/UnityVersion.Operators.cs

@@ -32,7 +32,7 @@ public readonly partial struct UnityVersion
 	/// <returns></returns>
 	public static bool operator >(UnityVersion left, UnityVersion right)
 	{
-		return left.CompareTo(right) > 0;
+		return left.m_data > right.m_data;
 	}
 
 	/// <summary>
@@ -43,7 +43,7 @@ public readonly partial struct UnityVersion
 	/// <returns></returns>
 	public static bool operator >=(UnityVersion left, UnityVersion right)
 	{
-		return left.CompareTo(right) >= 0;
+		return left.m_data >= right.m_data;
 	}
 
 	/// <summary>
@@ -54,7 +54,7 @@ public readonly partial struct UnityVersion
 	/// <returns></returns>
 	public static bool operator <(UnityVersion left, UnityVersion right)
 	{
-		return left.CompareTo(right) < 0;
+		return left.m_data < right.m_data;
 	}
 
 	/// <summary>
@@ -65,6 +65,6 @@ public readonly partial struct UnityVersion
 	/// <returns></returns>
 	public static bool operator <=(UnityVersion left, UnityVersion right)
 	{
-		return left.CompareTo(right) <= 0;
+		return left.m_data <= right.m_data;
 	}
 }

AssetRipper.Primitives/UnityVersion.Parsing.cs

@@ -2,14 +2,8 @@
 using System.Text.RegularExpressions;
 
 namespace AssetRipper.Primitives;
-
 public readonly partial struct UnityVersion
 {
-	private static readonly Regex majorMinorRegex = new Regex(@"^([0-9]+)\.([0-9]+)$", RegexOptions.Compiled);
-	private static readonly Regex majorMinorBuildRegex = new Regex(@"^([0-9]+)\.([0-9]+)\.([0-9]+)$", RegexOptions.Compiled);
-	private static readonly Regex normalRegex = new Regex(@"^([0-9]+)\.([0-9]+)\.([0-9]+)\.?([abcfpx])([0-9]+)((?:.|[\r\n])+)?$", RegexOptions.Compiled);
-	private static readonly Regex chinaRegex = new Regex(@"^([0-9]+)\.([0-9]+)\.([0-9]+)\.?f1c([0-9]+)((?:.|[\r\n])+)?$", RegexOptions.Compiled);
-	
 	/// <summary>
 	/// Serialize the version as a string using <see cref="UnityVersionFormatFlags.Default"/>.
 	/// </summary>
@@ -98,7 +92,7 @@ public readonly partial struct UnityVersion
 			version = default;
 			return false;
 		}
-		else if (chinaRegex.TryMatch(s, out Match? match))
+		else if (UnityVersionRegexes.GetChinaRegex().TryMatch(s, out Match? match))
 		{
 			int major = int.Parse(match.Groups[1].Value);
 			int minor = int.Parse(match.Groups[2].Value);
@@ -108,7 +102,7 @@ public readonly partial struct UnityVersion
 			version = new UnityVersion((ushort)major, (ushort)minor, (ushort)build, UnityVersionType.China, (byte)typeNumber);
 			return true;
 		}
-		else if(normalRegex.TryMatch(s, out match))
+		else if(UnityVersionRegexes.GetNormalRegex().TryMatch(s, out match))
 		{
 			int major = int.Parse(match.Groups[1].Value);
 			int minor = int.Parse(match.Groups[2].Value);
@@ -119,21 +113,34 @@ public readonly partial struct UnityVersion
 			version = new UnityVersion((ushort)major, (ushort)minor, (ushort)build, type.ToUnityVersionType(), (byte)typeNumber);
 			return true;
 		}
-		else if (majorMinorBuildRegex.TryMatch(s, out match))
+		else if (UnityVersionRegexes.GetMajorMinorBuildRegex().TryMatch(s, out match))
 		{
 			int major = int.Parse(match.Groups[1].Value);
 			int minor = int.Parse(match.Groups[2].Value);
 			int build = int.Parse(match.Groups[3].Value);
 			customEngine = null;
-			version = new UnityVersion((ushort)major, (ushort)minor, (ushort)build, UnityVersionType.Final, 1);
+			version = major is not 0 || minor is not 0 || build is not 0
+				? new UnityVersion((ushort)major, (ushort)minor, (ushort)build, UnityVersionType.Final, 1)
+				: default;
 			return true;
 		}
-		else if (majorMinorRegex.TryMatch(s, out match))
+		else if (UnityVersionRegexes.GetMajorMinorRegex().TryMatch(s, out match))
 		{
 			int major = int.Parse(match.Groups[1].Value);
 			int minor = int.Parse(match.Groups[2].Value);
 			customEngine = null;
-			version = new UnityVersion((ushort)major, (ushort)minor, 0, UnityVersionType.Final, 1);
+			version = major is not 0 || minor is not 0
+				? new UnityVersion((ushort)major, (ushort)minor, 0, UnityVersionType.Final, 1)
+				: default;
+			return true;
+		}
+		else if (UnityVersionRegexes.GetMajorRegex().TryMatch(s, out match))
+		{
+			int major = int.Parse(match.Groups[1].Value);
+			customEngine = null;
+			version = major is not 0
+				? new UnityVersion((ushort)major, 0, 0, UnityVersionType.Final, 1)
+				: default;
 			return true;
 		}
 		else

AssetRipper.Primitives/UnityVersionRegexes.cs

@@ -0,0 +1,68 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Text.RegularExpressions;
+
+namespace AssetRipper.Primitives;
+
+internal static partial class UnityVersionRegexes
+{
+#if NET35
+	private const RegexOptions Options = RegexOptions.None;
+#else
+	private const RegexOptions Options = RegexOptions.Compiled;
+#endif
+
+	[StringSyntax("regex")]
+	private const string Major = @"([0-9]+)";
+
+	[StringSyntax("regex")]
+	private const string MajorMinor = @"([0-9]+)\.([0-9]+)";
+
+	[StringSyntax("regex")]
+	private const string MajorMinorBuild = @"([0-9]+)\.([0-9]+)\.([0-9]+)";
+
+	[StringSyntax("regex")]
+	private const string Normal = @"([0-9]+)\.([0-9]+)\.([0-9]+)\.?([abcfpx])([0-9]+)((?:.|[\r\n])+)?";
+
+	[StringSyntax("regex")]
+	private const string China = @"([0-9]+)\.([0-9]+)\.([0-9]+)\.?f1c([0-9]+)((?:.|[\r\n])+)?";
+
+#if NET7_0_OR_GREATER
+	[GeneratedRegex(Major, Options)]
+	public static partial Regex GetMajorRegex();
+#else
+	private static readonly Regex majorRegex = new Regex(Major, Options);
+	public static Regex GetMajorRegex() => majorRegex;
+#endif
+
+#if NET7_0_OR_GREATER
+	[GeneratedRegex(MajorMinor, Options)]
+	public static partial Regex GetMajorMinorRegex();
+#else
+	private static readonly Regex majorMinorRegex = new Regex(MajorMinor, Options);
+	public static Regex GetMajorMinorRegex() => majorMinorRegex;
+#endif
+
+#if NET7_0_OR_GREATER
+	[GeneratedRegex(MajorMinorBuild, Options)]
+	public static partial Regex GetMajorMinorBuildRegex();
+#else
+	private static readonly Regex majorMinorBuildRegex = new Regex(MajorMinorBuild, Options);
+	public static Regex GetMajorMinorBuildRegex() => majorMinorBuildRegex;
+#endif
+
+#if NET7_0_OR_GREATER
+	[GeneratedRegex(Normal, Options)]
+	public static partial Regex GetNormalRegex();
+#else
+	private static readonly Regex normalRegex = new Regex(Normal, Options);
+	public static Regex GetNormalRegex() => normalRegex;
+#endif
+
+#if NET7_0_OR_GREATER
+	[GeneratedRegex(China, Options)]
+	public static partial Regex GetChinaRegex();
+#else
+	private static readonly Regex chinaRegex = new Regex(China, Options);
+	public static Regex GetChinaRegex() => chinaRegex;
+#endif
+}

AssetRipper.Primitives/Utf8String.cs

@@ -1,4 +1,4 @@
-#if NET7_0_OR_GREATER
+#if NET5_0_OR_GREATER || NETSTANDARD2_0_OR_GREATER || NET461_OR_GREATER
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Text;
@@ -11,7 +11,12 @@ namespace AssetRipper.Primitives;
 /// <remarks>
 /// Conversions to and from <see cref="string"/> are handled by <see cref="Encoding.UTF8"/>.
 /// </remarks>
-public sealed class Utf8String : IEquatable<Utf8String>
+public sealed class Utf8String :
+#if NET7_0_OR_GREATER
+	System.Numerics.IEqualityOperators<Utf8String?, Utf8String?, bool>,
+    System.Numerics.IEqualityOperators<Utf8String?, string?, bool>,
+#endif
+    IEquatable<Utf8String>
 {
 	private readonly byte[] data;
 	private string? cachedString;
@@ -60,7 +65,14 @@ public sealed class Utf8String : IEquatable<Utf8String>
 	public override int GetHashCode()
 	{
 		HashCode hash = new();
+#if NET6_0_OR_GREATER
 		hash.AddBytes(data);
+#else
+		foreach (byte b in data)
+		{
+			hash.Add(b);
+		}
+#endif
 		return hash.ToHashCode();
 	}
 
@@ -198,7 +210,10 @@ public sealed class Utf8String : IEquatable<Utf8String>
 
 	public static Utf8String Concat(params Utf8String?[] values)
 	{
-		ArgumentNullException.ThrowIfNull(values);
+		if (values is null)
+		{
+			throw new ArgumentNullException(nameof(values));
+		}
 
 		int totalLength = 0;
 		foreach (Utf8String? value in values)