diff --git a/api_list.include.md b/api_list.include.md
index 4aabfb95..0b3be03c 100644
--- a/api_list.include.md
+++ b/api_list.include.md
@@ -1125,6 +1125,7 @@
  * `StringBuilder Insert(int, ReadOnlySpan<char>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.insert?view=net-11.0#system-text-stringbuilder-insert(system-int32-system-readonlyspan((system-char))))
  * `StringBuilder Replace(ReadOnlySpan<char>, ReadOnlySpan<char>, int, int)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.replace?view=net-11.0#system-text-stringbuilder-replace(system-char-system-char-system-int32-system-int32))
  * `StringBuilder Replace(ReadOnlySpan<char>, ReadOnlySpan<char>)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.replace?view=net-11.0#system-text-stringbuilder-replace(system-readonlyspan((system-char))-system-readonlyspan((system-char))))
+ * `StringBuilder MoveChunks(StringBuilder)` [reference](https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.movechunks?view=net-11.0)
 
 
 #### Task
diff --git a/src/Consume/Consume.cs b/src/Consume/Consume.cs
index 54afd335..d839bc64 100644
--- a/src/Consume/Consume.cs
+++ b/src/Consume/Consume.cs
@@ -1526,6 +1526,7 @@ void DefaultInterpolatedStringHandler_Methods()
     void StringBuilder_Methods()
     {
         var builder = new StringBuilder("value");
+        var moved = StringBuilder.MoveChunks(builder);
 #if FeatureMemory
         builder.Append("suffix".AsSpan());
         var targetSpan = new Span<char>(new char[1]);
diff --git a/src/Polyfill/StringBuilderPolyfill.cs b/src/Polyfill/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..860747ce
--- /dev/null
+++ b/src/Polyfill/StringBuilderPolyfill.cs
@@ -0,0 +1,63 @@
+#if !NET12_0_OR_GREATER
+
+namespace Polyfills;
+
+using System;
+using System.Reflection;
+using System.Text;
+
+static partial class Polyfill
+{
+    extension(StringBuilder)
+    {
+        /// <summary>
+        /// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+        /// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+        /// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+        /// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+        /// is preserved.
+        /// </summary>
+        //Link: https://learn.microsoft.com/en-us/dotnet/api/system.text.stringbuilder.movechunks?view=net-11.0
+        public static StringBuilder MoveChunks(StringBuilder source)
+        {
+            if (source is null)
+            {
+                throw new ArgumentNullException(nameof(source));
+            }
+
+            var charsField = MoveChunksFields.ChunkChars;
+            var previousField = MoveChunksFields.ChunkPrevious;
+            var lengthField = MoveChunksFields.ChunkLength;
+            var offsetField = MoveChunksFields.ChunkOffset;
+            var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+
+            var destination = new StringBuilder(0, maxCapacity);
+            charsField.SetValue(destination, charsField.GetValue(source));
+            previousField.SetValue(destination, previousField.GetValue(source));
+            lengthField.SetValue(destination, lengthField.GetValue(source));
+            offsetField.SetValue(destination, offsetField.GetValue(source));
+
+            charsField.SetValue(source, Array.Empty<char>());
+            previousField.SetValue(source, null);
+            lengthField.SetValue(source, 0);
+            offsetField.SetValue(source, 0);
+
+            return destination;
+        }
+    }
+
+    static class MoveChunksFields
+    {
+        internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+        internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+        internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+        internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+        internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+
+        static FieldInfo GetField(string name) =>
+            typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+            throw new($"Expected to find field '{name}' on StringBuilder");
+    }
+}
+
+#endif
diff --git a/src/Split/net10.0/StringBuilderPolyfill.cs b/src/Split/net10.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net10.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net11.0/StringBuilderPolyfill.cs b/src/Split/net11.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net11.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net461/StringBuilderPolyfill.cs b/src/Split/net461/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net461/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net462/StringBuilderPolyfill.cs b/src/Split/net462/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net462/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net47/StringBuilderPolyfill.cs b/src/Split/net47/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net47/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net471/StringBuilderPolyfill.cs b/src/Split/net471/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net471/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net472/StringBuilderPolyfill.cs b/src/Split/net472/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net472/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net48/StringBuilderPolyfill.cs b/src/Split/net48/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net48/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net481/StringBuilderPolyfill.cs b/src/Split/net481/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net481/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net5.0/StringBuilderPolyfill.cs b/src/Split/net5.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net5.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net6.0/StringBuilderPolyfill.cs b/src/Split/net6.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net6.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net7.0/StringBuilderPolyfill.cs b/src/Split/net7.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net7.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net8.0/StringBuilderPolyfill.cs b/src/Split/net8.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net8.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/net9.0/StringBuilderPolyfill.cs b/src/Split/net9.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/net9.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netcoreapp2.0/StringBuilderPolyfill.cs b/src/Split/netcoreapp2.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netcoreapp2.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netcoreapp2.1/StringBuilderPolyfill.cs b/src/Split/netcoreapp2.1/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netcoreapp2.1/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netcoreapp2.2/StringBuilderPolyfill.cs b/src/Split/netcoreapp2.2/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netcoreapp2.2/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netcoreapp3.0/StringBuilderPolyfill.cs b/src/Split/netcoreapp3.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netcoreapp3.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netcoreapp3.1/StringBuilderPolyfill.cs b/src/Split/netcoreapp3.1/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netcoreapp3.1/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netstandard2.0/StringBuilderPolyfill.cs b/src/Split/netstandard2.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netstandard2.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/netstandard2.1/StringBuilderPolyfill.cs b/src/Split/netstandard2.1/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/netstandard2.1/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Split/uap10.0/StringBuilderPolyfill.cs b/src/Split/uap10.0/StringBuilderPolyfill.cs
new file mode 100644
index 00000000..cddb85db
--- /dev/null
+++ b/src/Split/uap10.0/StringBuilderPolyfill.cs
@@ -0,0 +1,54 @@
+// <auto-generated />
+#pragma warning disable
+#if !NET12_0_OR_GREATER
+namespace Polyfills;
+using System;
+using System.Reflection;
+using System.Text;
+static partial class Polyfill
+{
+	extension(StringBuilder)
+	{
+		/// <summary>
+		/// Creates a new <see cref="StringBuilder"/> instance initialized to the same state as
+		/// <paramref name="source"/>, and resets <paramref name="source"/> to an empty, usable state
+		/// with no allocated buffers. Ownership of the chunks is transferred in O(1); the underlying
+		/// character data is not copied. <paramref name="source"/>'s <see cref="StringBuilder.MaxCapacity"/>
+		/// is preserved.
+		/// </summary>
+		public static StringBuilder MoveChunks(StringBuilder source)
+		{
+			if (source is null)
+			{
+				throw new ArgumentNullException(nameof(source));
+			}
+			var charsField = MoveChunksFields.ChunkChars;
+			var previousField = MoveChunksFields.ChunkPrevious;
+			var lengthField = MoveChunksFields.ChunkLength;
+			var offsetField = MoveChunksFields.ChunkOffset;
+			var maxCapacity = (int) MoveChunksFields.MaxCapacity.GetValue(source)!;
+			var destination = new StringBuilder(0, maxCapacity);
+			charsField.SetValue(destination, charsField.GetValue(source));
+			previousField.SetValue(destination, previousField.GetValue(source));
+			lengthField.SetValue(destination, lengthField.GetValue(source));
+			offsetField.SetValue(destination, offsetField.GetValue(source));
+			charsField.SetValue(source, Array.Empty<char>());
+			previousField.SetValue(source, null);
+			lengthField.SetValue(source, 0);
+			offsetField.SetValue(source, 0);
+			return destination;
+		}
+	}
+	static class MoveChunksFields
+	{
+		internal static readonly FieldInfo ChunkChars = GetField("m_ChunkChars");
+		internal static readonly FieldInfo ChunkPrevious = GetField("m_ChunkPrevious");
+		internal static readonly FieldInfo ChunkLength = GetField("m_ChunkLength");
+		internal static readonly FieldInfo ChunkOffset = GetField("m_ChunkOffset");
+		internal static readonly FieldInfo MaxCapacity = GetField("m_MaxCapacity");
+		static FieldInfo GetField(string name) =>
+			typeof(StringBuilder).GetField(name, BindingFlags.Instance | BindingFlags.NonPublic) ??
+			throw new($"Expected to find field '{name}' on StringBuilder");
+	}
+}
+#endif
diff --git a/src/Tests/PolyfillTests_StringBuilder.cs b/src/Tests/PolyfillTests_StringBuilder.cs
index 800b8a7b..ad42616d 100644
--- a/src/Tests/PolyfillTests_StringBuilder.cs
+++ b/src/Tests/PolyfillTests_StringBuilder.cs
@@ -90,6 +90,29 @@ public async Task AppendLineWithFormat()
         await Assert.That(builder.ToString()).IsEqualTo("value10" + Environment.NewLine);
     }
 
+    [Test]
+    public async Task MoveChunks()
+    {
+        var source = new StringBuilder("hello", 10);
+        var maxCapacity = source.MaxCapacity;
+
+        var destination = StringBuilder.MoveChunks(source);
+
+        await Assert.That(destination.ToString()).IsEqualTo("hello");
+        await Assert.That(destination.MaxCapacity).IsEqualTo(maxCapacity);
+
+        await Assert.That(source.Length).IsEqualTo(0);
+        await Assert.That(source.Capacity).IsEqualTo(0);
+        await Assert.That(source.MaxCapacity).IsEqualTo(maxCapacity);
+
+        source.Append('x');
+        await Assert.That(source.ToString()).IsEqualTo("x");
+    }
+
+    [Test]
+    public async Task MoveChunks_Null_Throws() =>
+        await Assert.That(() => StringBuilder.MoveChunks(null!)).Throws<ArgumentNullException>();
+
     [Test]
     public async Task StringBuilder_Insert_ReadOnlySpan()
     {