Cysharp · MarkKharitonov · Jun 21, 2025 · Jun 21, 2025
diff --git a/sandbox/ConsoleApp/ConsoleApp.csproj b/sandbox/ConsoleApp/ConsoleApp.csproj
@@ -2,15 +2,15 @@
 
 	<PropertyGroup>
 		<OutputType>Exe</OutputType>
-		<TargetFramework>net7.0</TargetFramework>
+		<TargetFramework>net9.0</TargetFramework>
 		<SignAssembly>true</SignAssembly>
 		<AssemblyOriginatorKeyFile>../../opensource.snk</AssemblyOriginatorKeyFile>
 		<IsPackable>false</IsPackable>
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="BenchmarkDotNet" Version="0.12.1" />
-		<PackageReference Include="System.Text.Json" Version="8.0.4" />
+		<PackageReference Include="BenchmarkDotNet" Version="0.15.2" />
+		<PackageReference Include="System.Text.Json" Version="9.0.6" />
 		<ProjectReference Include="..\..\src\ZString\ZString.csproj">
 			<SetTargetFramework>TargetFramework=netstandard2.1</SetTargetFramework>
 		</ProjectReference>

diff --git a/sandbox/PerfBenchmark/PerfBenchmark.csproj b/sandbox/PerfBenchmark/PerfBenchmark.csproj
@@ -2,13 +2,13 @@
 
 	<PropertyGroup>
 		<OutputType>Exe</OutputType>
-		<TargetFramework>net6.0</TargetFramework>
+		<TargetFramework>net9.0</TargetFramework>
 		<LangVersion>8.0</LangVersion>
 		<IsPackable>false</IsPackable>
 	</PropertyGroup>
 
 	<ItemGroup>
-		<PackageReference Include="BenchmarkDotNet" Version="0.12.1" />
+		<PackageReference Include="BenchmarkDotNet" Version="0.15.2" />
 		<PackageReference Include="StringFormatter" Version="1.0.0.13" />
 	</ItemGroup>
 

diff --git a/src/ZString.Unity/Assets/Scripts/ZString/EnumUtil.cs b/src/ZString.Unity/Assets/Scripts/ZString/EnumUtil.cs
@@ -6,7 +6,7 @@
 namespace Cysharp.Text
 {
     internal static class EnumUtil<T>
-        // where T : Enum
+        where T : notnull
     {
         const string InvalidName = "$";
 
@@ -45,7 +45,7 @@ public static bool TryFormatUtf16(T value, Span<char> dest, out int written, Rea
         {
             if (!names.TryGetValue(value, out var v) || v == InvalidName)
             {
-                v = value!.ToString(); // T is Enum, not null always
+                v = value!.ToString()!; // T is Enum, not null always
             }
 
             written = v.Length;
@@ -56,7 +56,7 @@ public static bool TryFormatUtf8(T value, Span<byte> dest, out int written, Stan
         {
             if (!utf8names.TryGetValue(value, out var v) || v.Length == 0)
             {
-                v = Encoding.UTF8.GetBytes(value!.ToString());
+                v = Encoding.UTF8.GetBytes(value.ToString()!);
             }
 
             written = v.Length;

diff --git a/src/ZString.Unity/Assets/Scripts/ZString/FormatHelper.cs b/src/ZString.Unity/Assets/Scripts/ZString/FormatHelper.cs
@@ -47,7 +47,7 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         {
             if (typeof(T) == typeof(string))
             {
-                var s = Unsafe.As<string>(arg);
+                var s = Unsafe.As<string>(arg) ?? "";
                 int padding = width - s.Length;
                 if (padding > 0)
                 {
@@ -130,7 +130,7 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         {
             if (typeof(T) == typeof(string))
             {
-                var s = Unsafe.As<string>(arg);
+                var s = Unsafe.As<string>(arg) ?? "";
                 int padding = width - s.Length;
                 if (padding > 0)
                 {
@@ -169,4 +169,4 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         }
     }
 
-}
+}
diff --git a/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.BigInteger.cs b/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.BigInteger.cs
@@ -7,6 +7,8 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
+#pragma warning disable CS9080,CS9082,CS9084,CS9091,CS9094
+
 namespace System
 {
     internal static partial class Number
@@ -1219,4 +1221,4 @@ private static uint DivRem32(uint value, out uint remainder)
             }
         }
     }
-}
+}
diff --git a/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.Dragon4.cs b/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.Dragon4.cs
@@ -6,6 +6,9 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 
+#pragma warning disable CS9080
+#pragma warning disable CS9091
+
 namespace System
 {
     // This is a port of the `Dragon4` implementation here: http://www.ryanjuckett.com/programming/printing-floating-point-numbers/part-2/
@@ -522,4 +525,4 @@ private static unsafe uint Dragon4(ulong mantissa, int exponent, uint mantissaHi
             return outputLen;
         }
     }
-}
+}
diff --git a/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.NumberToFloatingPointBits.cs b/src/ZString.Unity/Assets/Scripts/ZString/Number/Number.NumberToFloatingPointBits.cs
@@ -5,6 +5,8 @@
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
+#pragma warning disable CS9080
+
 namespace System
 {
     internal unsafe partial class Number
@@ -634,4 +636,4 @@ private static bool ShouldRoundUp(bool lsbBit, bool roundBit, bool hasTailBits)
             return roundBit && (hasTailBits || lsbBit);
         }
     }
-}
+}
diff --git a/src/ZString.Unity/Assets/Scripts/ZString/Utf16ValueStringBuilder.cs b/src/ZString.Unity/Assets/Scripts/ZString/Utf16ValueStringBuilder.cs
@@ -40,7 +40,7 @@ static Utf16ValueStringBuilder()
         [ThreadStatic]
         internal static bool scratchBufferUsed;
 
-        char[]? buffer;
+        char[] buffer;
         int index;
         bool disposeImmediately;
 
@@ -103,7 +103,7 @@ public void Dispose()
                 {
                     ArrayPool<char>.Shared.Return(buffer);
                 }
-                buffer = null;
+                buffer = null!;
                 index = 0;
                 if (disposeImmediately)
                 {
@@ -642,7 +642,7 @@ void AppendFormatInternal<T>(T arg, int width, ReadOnlySpan<char> format, string
             {
                 if (typeof(T) == typeof(string))
                 {
-                    var s = Unsafe.As<string>(arg);
+                    var s = Unsafe.As<string>(arg) ?? "";
                     int padding = width - s.Length;
                     if (padding > 0)
                     {
@@ -719,7 +719,9 @@ static FormatterCache()
                 {
                     if (typeof(T).IsEnum)
                     {
+#pragma warning disable CS8714
                         formatter = new TryFormat<T>(EnumUtil<T>.TryFormatUtf16);
+#pragma warning restore CS8714
                     }
                     else if (typeof(T) == typeof(string))
                     {
@@ -759,7 +761,7 @@ static bool TryFormatDefault(T value, Span<char> dest, out int written, ReadOnly
 
                 var s = (value is IFormattable formattable && format.Length != 0) ?
                     formattable.ToString(format.ToString(), null) :
-                    value.ToString();
+                    value.ToString()!;
 
                 // also use this length when result is false.
                 written = s.Length;

diff --git a/src/ZString.Unity/Assets/Scripts/ZString/Utf8ValueStringBuilder.cs b/src/ZString.Unity/Assets/Scripts/ZString/Utf8ValueStringBuilder.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Buffers;
 using System.IO;
 using System.Runtime.CompilerServices;
@@ -44,7 +44,7 @@ static Utf8ValueStringBuilder()
         [ThreadStatic]
         internal static bool scratchBufferUsed;
 
-        byte[]? buffer;
+        byte[] buffer;
         int index;
         bool disposeImmediately;
 
@@ -110,7 +110,7 @@ public void Dispose()
                 {
                     ArrayPool<byte>.Shared.Return(buffer);
                 }
-                buffer = null;
+                buffer = null!;
                 index = 0;
                 if (disposeImmediately)
                 {
@@ -432,7 +432,7 @@ private void AppendFormatInternal<T>(T arg, int width, StandardFormat format, st
             {
                 if (typeof(T) == typeof(string))
                 {
-                    var s = Unsafe.As<string>(arg);
+                    var s = Unsafe.As<string>(arg) ?? "";
                     int padding = width - s.Length;
                     if (padding > 0)
                     {
@@ -504,8 +504,10 @@ static FormatterCache()
                 if (formatter == null)
                 {
                     if (typeof(T).IsEnum)
-                    {
-                        formatter = new TryFormat<T>(EnumUtil<T>.TryFormatUtf8);
+                    {
+#pragma warning disable CS8714
+                        formatter = new TryFormat<T>(EnumUtil<T>.TryFormatUtf8);
+#pragma warning restore CS8714
                     }
                     else
                     {
@@ -526,7 +528,7 @@ static bool TryFormatDefault(T value, Span<byte> dest, out int written, Standard
 
                 var s = typeof(T) == typeof(string) ? Unsafe.As<string>(value) :
                     (value is IFormattable formattable && format != default) ? formattable.ToString(format.ToString(), null) :
-                    value.ToString();
+                    value.ToString()!;
 
                 // also use this length when result is false.
                 written = UTF8NoBom.GetMaxByteCount(s.Length);

diff --git a/src/ZString.Unity/Assets/Scripts/ZString/ZString.cs b/src/ZString.Unity/Assets/Scripts/ZString/ZString.cs
@@ -270,7 +270,7 @@ static string JoinInternal<T>(ReadOnlySpan<char> separator, ReadOnlySpan<T> valu
             }
             else if (typeof(T) == typeof(string) && values.Length == 1)
             {
-                return Unsafe.As<string>(values[0]);
+                return Unsafe.As<string>(values[0])!;
             }
 
             var sb = new Utf16ValueStringBuilder(true);

diff --git a/src/ZString.Unity/Assets/Scripts/ZString/ZStringWriter.cs b/src/ZString.Unity/Assets/Scripts/ZString/ZStringWriter.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Globalization;
 using System.IO;
 using System.Text;
@@ -82,7 +82,7 @@ public override void Write(char[] buffer, int index, int count)
             sb.Append(buffer, index, count);
         }
 
-        public override void Write(string value)
+        public override void Write(string? value)
         {
             AssertNotDisposed();
 
@@ -98,7 +98,7 @@ public override Task WriteAsync(char value)
             return Task.CompletedTask;
         }
 
-        public override Task WriteAsync(string value)
+        public override Task WriteAsync(string? value)
         {
             Write(value);
             return Task.CompletedTask;
@@ -116,7 +116,7 @@ public override Task WriteLineAsync(char value)
             return Task.CompletedTask;
         }
 
-        public override Task WriteLineAsync(string value)
+        public override Task WriteLineAsync(string? value)
         {
             WriteLine(value);
             return Task.CompletedTask;

diff --git a/src/ZString/EnumUtil.cs b/src/ZString/EnumUtil.cs
@@ -6,7 +6,7 @@
 namespace Cysharp.Text
 {
     internal static class EnumUtil<T>
-        // where T : Enum
+        where T : notnull
     {
         const string InvalidName = "$";
 
@@ -45,7 +45,7 @@ public static bool TryFormatUtf16(T value, Span<char> dest, out int written, Rea
         {
             if (!names.TryGetValue(value, out var v) || v == InvalidName)
             {
-                v = value!.ToString(); // T is Enum, not null always
+                v = value!.ToString()!; // T is Enum, not null always
             }
 
             written = v.Length;
@@ -56,7 +56,7 @@ public static bool TryFormatUtf8(T value, Span<byte> dest, out int written, Stan
         {
             if (!utf8names.TryGetValue(value, out var v) || v.Length == 0)
             {
-                v = Encoding.UTF8.GetBytes(value!.ToString());
+                v = Encoding.UTF8.GetBytes(value.ToString()!);
             }
 
             written = v.Length;

diff --git a/src/ZString/FormatHelper.cs b/src/ZString/FormatHelper.cs
@@ -47,7 +47,7 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         {
             if (typeof(T) == typeof(string))
             {
-                var s = Unsafe.As<string>(arg);
+                var s = Unsafe.As<string>(arg) ?? "";
                 int padding = width - s.Length;
                 if (padding > 0)
                 {
@@ -130,7 +130,7 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         {
             if (typeof(T) == typeof(string))
             {
-                var s = Unsafe.As<string>(arg);
+                var s = Unsafe.As<string>(arg) ?? "";
                 int padding = width - s.Length;
                 if (padding > 0)
                 {
@@ -169,4 +169,4 @@ private static void FormatToRightJustify<TBufferWriter, T>(ref TBufferWriter sb,
         }
     }
 
-}
+}
diff --git a/src/ZString/FormatHelper.tt b/src/ZString/FormatHelper.tt
@@ -1,4 +1,4 @@
-<#@ template debug="false" hostspecific="false" language="C#" #>
+<#@ template debug="false" hostspecific="false" language="C#" #>
 <#@ assembly name="System.Core" #>
 <#@ import namespace="System.Linq" #>
 <#@ import namespace="System.Text" #>
@@ -55,7 +55,7 @@ namespace Cysharp.Text
         {
             if (typeof(T) == typeof(string))
             {
-                var s = Unsafe.As<string>(arg);
+                var s = Unsafe.As<string>(arg) ?? "";
                 int padding = width - s.Length;
                 if (padding > 0)
                 {
@@ -101,4 +101,4 @@ namespace Cysharp.Text
     }
 
 <# } // foreach(utf) #>
-}
+}
diff --git a/src/ZString/Number/Number.BigInteger.cs b/src/ZString/Number/Number.BigInteger.cs
@@ -7,6 +7,8 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
+#pragma warning disable CS9080,CS9082,CS9084,CS9091,CS9094
+
 namespace System
 {
     internal static partial class Number
@@ -1219,4 +1221,4 @@ private static uint DivRem32(uint value, out uint remainder)
             }
         }
     }
-}
+}
diff --git a/src/ZString/Number/Number.Dragon4.cs b/src/ZString/Number/Number.Dragon4.cs
@@ -6,6 +6,9 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 
+#pragma warning disable CS9080
+#pragma warning disable CS9091
+
 namespace System
 {
     // This is a port of the `Dragon4` implementation here: http://www.ryanjuckett.com/programming/printing-floating-point-numbers/part-2/
@@ -522,4 +525,4 @@ private static unsafe uint Dragon4(ulong mantissa, int exponent, uint mantissaHi
             return outputLen;
         }
     }
-}
+}