some more things

Introduced StringEx and UnmanagedAnsiString for advanced string allocation and unmanaged string handling. Moved encoding and JSON-related files to SystemEx.Text namespaces. Updated Base32 API to use GetByteCount/GetCharCount. Added NonCopyableAttribute and applied it to relevant structs. Improved string allocation and writable span usage in StringExtensions and Polyfills. Updated project files for new dependencies and target frameworks.

Author: Xpl0itR

README.md

@@ -1,6 +1,6 @@
 SystemEx [![NuGet](https://img.shields.io/nuget/vpre/Xpl0itR.SystemEx)](https://www.nuget.org/packages/Xpl0itR.SystemEx/)
 ========
-SystemEx is a library which extends the functionality of the .NET standard libraries, written in C# 12, targeting .NET 8.0 and later.
+SystemEx is a library which extends the functionality of the .NET standard libraries.
 
 License
 -------

src/Cryptography/Otp/HOtp.cs

@@ -6,7 +6,7 @@
 
 using System;
 using System.Security.Cryptography;
-using SystemEx.Encoding;
+using SystemEx.Text.Encoding;
 
 namespace SystemEx.Cryptography.Otp;
 
@@ -52,7 +52,7 @@ public HOtp(ReadOnlySpan<char> keyBase32, HashAlgorithmName hashAlg)
 #else
         byte[] key = new byte
 #endif
-            [Base32.CountBytes(keyBase32.Length)];
+            [Base32.GetByteCount(keyBase32.Length)];
 
         Base32.GetBytesUnchecked(keyBase32, key);
 
@@ -66,6 +66,7 @@ public uint NumDigits
 
     public int ComputeCode(ReadOnlySpan<byte> counter)
     {
+        // ReSharper disable once InconsistentlySynchronizedField
         Span<byte> hash = stackalloc byte[_hmac.HashLengthInBytes];
 
         lock (_hmacLock)

src/Cryptography/Random/MT19937_64.Slim.cs

@@ -8,11 +8,13 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using CommunityToolkit.Diagnostics;
+using Microsoft.CodeAnalysis;
 
 namespace SystemEx.Cryptography.Random;
 
 partial class MT19937_64
 {
+    [NonCopyable]
     [StructLayout(LayoutKind.Auto)]
     public ref struct Slim
     {

src/Memory/MemoryReader.cs

@@ -9,9 +9,11 @@
 using System.Runtime.InteropServices;
 using CommunityToolkit.Diagnostics;
 using CommunityToolkit.HighPerformance;
+using Microsoft.CodeAnalysis;
 
 namespace SystemEx.Memory;
 
+[NonCopyable]
 [StructLayout(LayoutKind.Auto)]
 public ref partial struct MemoryReader
 {

src/Memory/MemoryWriter.cs

@@ -9,9 +9,11 @@
 using System.Runtime.InteropServices;
 using CommunityToolkit.Diagnostics;
 using CommunityToolkit.HighPerformance;
+using Microsoft.CodeAnalysis;
 
 namespace SystemEx.Memory;
 
+[NonCopyable]
 [StructLayout(LayoutKind.Auto)]
 public ref partial struct MemoryWriter
 {

src/Memory/StringEx.cs

@@ -0,0 +1,42 @@
+// Copyright © 2023-2025 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using CommunityToolkit.HighPerformance;
+
+namespace SystemEx.Memory;
+
+public static class StringEx
+{
+    extension(string str)
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public Span<char> AsWriteableSpan() =>
+            MemoryMarshal.CreateSpan(
+                ref str.DangerousGetReference(),
+                str.Length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static string Allocate(int length)
+        {
+#if NET9_0_OR_GREATER
+            return FastAllocateString(null, length);
+
+            [UnsafeAccessor(UnsafeAccessorKind.StaticMethod, Name = "FastAllocateString"), MethodImpl(MethodImplOptions.AggressiveInlining)]
+            static extern
+#if NET10_0_OR_GREATER
+            string FastAllocateString(string? _, nint length);
+#else
+            string FastAllocateString(string? _, int length);
+#endif
+#else
+            return new string('\0', length);
+#endif
+        }
+    }
+}

src/Memory/UnmanagedAnsiString.cs

@@ -0,0 +1,23 @@
+// Copyright © 2025 Xpl0itR
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace SystemEx.Memory;
+
+[method: MethodImpl(MethodImplOptions.AggressiveInlining)]
+public readonly struct UnmanagedAnsiString(string? str) : IDisposable
+{
+    public readonly nint Ptr = Marshal.StringToCoTaskMemAnsi(str);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public void Dispose() => Marshal.FreeCoTaskMem(Ptr);
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static implicit operator nint (UnmanagedAnsiString str) => str.Ptr;
+}

src/Memory/UnsafeEx.cs

@@ -50,12 +50,6 @@ public static ReadOnlySpan<byte> AsReadOnlyBytes<T>(this ref T value) where T :
             ref Unsafe.As<T, byte>(ref value),
             Unsafe.SizeOf<T>());
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static Span<char> AsWriteableSpan(this string str) =>
-        MemoryMarshal.CreateSpan(
-            ref str.DangerousGetReference(),
-            str.Length);
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static ref TTo As<TFrom, TTo>(ref TFrom ptr, int offset)
 #if NET9_0_OR_GREATER

src/Net/Http/RemoteContainer/CentralDirectory.cs

@@ -16,18 +16,17 @@ public sealed class CentralDirectory : IReadOnlyDictionary<string, CentralDirect
 {
     private readonly Dictionary<string, CentralDirectoryEntry> _centralDirEntries;
 
-    internal CentralDirectory(RentedArray<byte> buffer, ulong entryCount)
+    internal CentralDirectory(ref MemoryReader reader, ulong entryCount)
     {
         _centralDirEntries = new Dictionary<string, CentralDirectoryEntry>(
             entryCount > int.MaxValue
                 ? int.MaxValue
                 : (int)entryCount,
             StringComparer.Ordinal);
 
-        MemoryReader centralDirReader = new(buffer);
-        while (centralDirReader.Remaining > 0)
+        while (reader.Remaining > 0)
         {
-            CentralDirectoryEntry entry = new(ref centralDirReader);
+            CentralDirectoryEntry entry = new(ref reader);
             _centralDirEntries.Add(entry.FileName, entry);
         }
     }

src/Net/Http/RemoteContainer/RemoteZipArchive.cs

@@ -105,7 +105,9 @@ public static async Task<RemoteZipArchive> Open(HttpMessageInvoker http, Uri? ur
         using RentedArray<byte> centralDirBuffer = new(checked((int)centralDirLength));
         await http.ReadChunkAsync(centralDirBuffer, uri, eTag, checked((long)centralDirOffset), ct).ConfigureAwait(false);
 
-        CentralDirectory centralDirectory = new(centralDirBuffer, entryCount);
+        MemoryReader     centralDirReader = new(centralDirBuffer);
+        CentralDirectory centralDirectory = new(ref centralDirReader, entryCount);
+
         return new RemoteZipArchive(http, uri, eTag, centralDirectory);
     }
 }