Added pools, IndexedFishMap, IndexedFishSet, fixed bugs related to FishTable.Remove, added Preview.png, various smaller additions, some refactoring too

Source/FisheryLib/Pools/PooledStringBuilder.cs

@@ -0,0 +1,62 @@
+// Copyright (c) 2023 bradson
+// 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 https://mozilla.org/MPL/2.0/.
+
+using System.Security;
+using System.Text;
+using JetBrains.Annotations;
+
+namespace FisheryLib.Pools;
+
+public record struct PooledStringBuilder : IDisposable
+{
+	private FishPoolable _fishPoolable;
+	
+	public StringBuilder Builder => _fishPoolable.Builder;
+
+	public StringBuilder Append(string? value) => Builder.Append(value);
+	public StringBuilder Append(char value) => Builder.Append(value);
+	public StringBuilder Append(char[] value) => Builder.Append(value);
+	public StringBuilder Append(PooledStringBuilderHandler value) => value.AppendToStringBuilder(Builder);
+
+	public StringBuilder AppendLine(string? value) => Builder.AppendLine(value);
+	
+	public StringBuilder Insert(int index, string? value) => Builder.Insert(index, value);
+	public StringBuilder Insert(int index, char value) => Builder.Insert(index, value);
+	
+	public StringBuilder Remove(int startIndex, int length) => Builder.Remove(startIndex, length);
+
+	public void Clear() => Builder.Clear();
+
+	public override string ToString() => Builder.ToString();
+	
+	[SecuritySafeCritical]
+	public PooledStringBuilder() => _fishPoolable = FishPool<FishPoolable>.Get();
+
+	public PooledStringBuilder(int minimumSize) : this()
+	{
+		if (_fishPoolable.Builder.Capacity < minimumSize)
+			_fishPoolable.Builder.Capacity = minimumSize;
+	}
+
+	[SecuritySafeCritical]
+	public void Dispose()
+	{
+		if (_fishPoolable.Builder == null!)
+			return;
+
+		FishPool<FishPoolable>.Return(_fishPoolable);
+		_fishPoolable.Builder = null!;
+	}
+
+	private struct FishPoolable : IFishPoolable
+	{
+		public StringBuilder Builder = new();
+		
+		public void Reset() => Builder.Clear();
+		
+		[UsedImplicitly]
+		public FishPoolable() {}
+	}
+}