diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7daff2..4de5308 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - X10D: Added math-related extension methods for `BigInteger`.
 - X10D: Added `Span<T>.Replace(T, T)`.
 - X10D: Added `CountDigits` for integer types.
+- X10D: Added `TextWriter.WriteNoAlloc(int[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteNoAlloc(uint[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteNoAlloc(long[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteNoAlloc(ulong[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteLineNoAlloc(int[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteLineNoAlloc(uint[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteLineNoAlloc(long[, ReadOnlySpan<char>[, IFormatProvider]])`.
+- X10D: Added `TextWriter.WriteLineNoAlloc(ulong[, ReadOnlySpan<char>[, IFormatProvider]])`.
 
 ### Changed
 - X10D: `DateTime.Age(DateTime)` and `DateTimeOffset.Age(DateTimeOffset)` parameter renamed from `asOf` to `referenceDate`.
diff --git a/X10D.Tests/src/IO/TextWriterTests.Int32.cs b/X10D.Tests/src/IO/TextWriterTests.Int32.cs
new file mode 100644
index 0000000..31bed11
--- /dev/null
+++ b/X10D.Tests/src/IO/TextWriterTests.Int32.cs
@@ -0,0 +1,131 @@
+using System.Globalization;
+using System.Text;
+using NUnit.Framework;
+using X10D.IO;
+
+namespace X10D.Tests.IO;
+
+public partial class TextWriterTests
+{
+    [Test]
+    public void WriteNoAlloc_ShouldThrowArgumentNullException_GivenInt32_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldThrowObjectDisposedException_GivenInt32_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowArgumentNullException_GivenInt32_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowObjectDisposedException_GivenInt32_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt32()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt32_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt32_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt32()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt32_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt32_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+}
diff --git a/X10D.Tests/src/IO/TextWriterTests.Int64.cs b/X10D.Tests/src/IO/TextWriterTests.Int64.cs
new file mode 100644
index 0000000..affd830
--- /dev/null
+++ b/X10D.Tests/src/IO/TextWriterTests.Int64.cs
@@ -0,0 +1,131 @@
+using System.Globalization;
+using System.Text;
+using NUnit.Framework;
+using X10D.IO;
+
+namespace X10D.Tests.IO;
+
+public partial class TextWriterTests
+{
+    [Test]
+    public void WriteNoAlloc_ShouldThrowArgumentNullException_GivenInt64_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420L));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420L, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420L, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldThrowObjectDisposedException_GivenInt64_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420L));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420L, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420L, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowArgumentNullException_GivenInt64_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420L));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420L, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420L, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowObjectDisposedException_GivenInt64_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420L));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420L, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420L, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt64()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420L);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt64_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420L, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenInt64_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420L, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt64()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420L);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt64_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420L, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenInt64_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420L, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+}
diff --git a/X10D.Tests/src/IO/TextWriterTests.UInt32.cs b/X10D.Tests/src/IO/TextWriterTests.UInt32.cs
new file mode 100644
index 0000000..8aab080
--- /dev/null
+++ b/X10D.Tests/src/IO/TextWriterTests.UInt32.cs
@@ -0,0 +1,131 @@
+using System.Globalization;
+using System.Text;
+using NUnit.Framework;
+using X10D.IO;
+
+namespace X10D.Tests.IO;
+
+public partial class TextWriterTests
+{
+    [Test]
+    public void WriteNoAlloc_ShouldThrowArgumentNullException_GivenUInt32_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420U));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420U, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420U, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldThrowObjectDisposedException_GivenUInt32_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420U));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420U, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420U, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowArgumentNullException_GivenUInt32_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420U));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420U, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420U, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowObjectDisposedException_GivenUInt32_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420U));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420U, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420U, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt32()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420U);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt32_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420U, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt32_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420U, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt32()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420U);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt32_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420U, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt32_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420U, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+}
diff --git a/X10D.Tests/src/IO/TextWriterTests.UInt64.cs b/X10D.Tests/src/IO/TextWriterTests.UInt64.cs
new file mode 100644
index 0000000..57f5425
--- /dev/null
+++ b/X10D.Tests/src/IO/TextWriterTests.UInt64.cs
@@ -0,0 +1,131 @@
+using System.Globalization;
+using System.Text;
+using NUnit.Framework;
+using X10D.IO;
+
+namespace X10D.Tests.IO;
+
+public partial class TextWriterTests
+{
+    [Test]
+    public void WriteNoAlloc_ShouldThrowArgumentNullException_GivenUInt64_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420UL));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420UL, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteNoAlloc(420UL, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldThrowObjectDisposedException_GivenUInt64_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420UL));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420UL, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteNoAlloc(420UL, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowArgumentNullException_GivenUInt64_AndNullWriter()
+    {
+        TextWriter writer = null!;
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420UL));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420UL, "N0"));
+        Assert.Throws<ArgumentNullException>(() => writer.WriteLineNoAlloc(420UL, "N0", null));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldThrowObjectDisposedException_GivenUInt64_AndDisposedStream()
+    {
+        var stream = new MemoryStream();
+        var writer = new StreamWriter(stream, Encoding.UTF8);
+        writer.Dispose();
+        stream.Dispose();
+
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420UL));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420UL, "N0"));
+        Assert.Throws<ObjectDisposedException>(() => writer.WriteLineNoAlloc(420UL, "N0", null));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt64()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420UL);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt64_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420UL, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteNoAlloc_ShouldWriteTextValue_GivenUInt64_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteNoAlloc(420UL, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        const string expected = "420";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt64()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420UL);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt64_AndFormatString()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420UL, "N0");
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void WriteLineNoAlloc_ShouldWriteTextValue_GivenUInt64_AndFormatString_AndCultureInfo()
+    {
+        Assert.That(_stream.Length, Is.Zero);
+        _writer.WriteLineNoAlloc(420UL, "N0", CultureInfo.CurrentCulture);
+        _writer.Flush();
+
+        string actual = Encoding.UTF8.GetString(_stream.ToArray());
+        var expected = $"420{Environment.NewLine}";
+
+        Assert.That(actual, Is.EqualTo(expected));
+    }
+}
diff --git a/X10D.Tests/src/IO/TextWriterTests.cs b/X10D.Tests/src/IO/TextWriterTests.cs
new file mode 100644
index 0000000..b98268a
--- /dev/null
+++ b/X10D.Tests/src/IO/TextWriterTests.cs
@@ -0,0 +1,46 @@
+using System.Diagnostics;
+using System.Text;
+using NUnit.Framework;
+
+namespace X10D.Tests.IO;
+
+[TestFixture]
+public partial class TextWriterTests
+{
+    private MemoryStream _stream = null!;
+    private StreamWriter _writer = null!;
+
+    [OneTimeSetUp]
+    public void OneTimeSetup()
+    {
+        _stream = new MemoryStream();
+        _writer = new StreamWriter(_stream, Encoding.UTF8);
+        _writer.Write(' ');
+        _writer.Flush();
+        _stream.SetLength(0);
+        _stream.Position = 0;
+
+        Trace.Listeners.Add(new ConsoleTraceListener());
+    }
+
+    [OneTimeTearDown]
+    public void OneTimeTearDown()
+    {
+        _writer.Dispose();
+        _stream.Dispose();
+
+        Trace.Flush();
+    }
+
+    [SetUp]
+    public void Setup()
+    {
+        _stream.SetLength(0);
+    }
+
+    [TearDown]
+    public void TearDown()
+    {
+        _stream.SetLength(0);
+    }
+}
diff --git a/X10D/src/IO/TextWriterExtensions.cs b/X10D/src/IO/TextWriterExtensions.cs
new file mode 100644
index 0000000..7d1b3c5
--- /dev/null
+++ b/X10D/src/IO/TextWriterExtensions.cs
@@ -0,0 +1,685 @@
+using System.Globalization;
+using X10D.Math;
+
+namespace X10D.IO;
+
+/// <summary>
+///     IO-related extension methods for <see cref="TextWriter" />.
+/// </summary>
+public static class TextWriterExtensions
+{
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer, int value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer, int value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer, int value, ReadOnlySpan<char> format, IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        int digitCount = value.CountDigits();
+        Span<char> buffer = stackalloc char[System.Math.Max(value < 0 ? digitCount + 1 : digitCount, 1000)];
+        if (value.TryFormat(buffer, out int charsWritten, format, formatProvider))
+        {
+            Span<char> truncated = buffer[..charsWritten];
+            for (var index = 0; index < truncated.Length; index++)
+            {
+                writer.Write(truncated[index]);
+            }
+        }
+        else
+        {
+            writer.Write(value.ToString(format.ToString(), formatProvider));
+        }
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer, uint value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer, uint value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer,
+        uint value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        int digitCount = value.CountDigits();
+        Span<char> buffer = stackalloc char[System.Math.Max(digitCount, 1000)];
+        if (value.TryFormat(buffer, out int charsWritten, format, formatProvider))
+        {
+            Span<char> truncated = buffer[..charsWritten];
+            for (var index = 0; index < truncated.Length; index++)
+            {
+                writer.Write(truncated[index]);
+            }
+        }
+        else
+        {
+            writer.Write(value.ToString(format.ToString(), formatProvider));
+        }
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer, long value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer, long value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteNoAlloc(this TextWriter writer,
+        long value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        int digitCount = value.CountDigits();
+        Span<char> buffer = stackalloc char[System.Math.Max(value < 0 ? digitCount + 1 : digitCount, 1000)];
+        if (value.TryFormat(buffer, out int charsWritten, format, formatProvider))
+        {
+            Span<char> truncated = buffer[..charsWritten];
+            for (var index = 0; index < truncated.Length; index++)
+            {
+                writer.Write(truncated[index]);
+            }
+        }
+        else
+        {
+            writer.Write(value.ToString(format.ToString(), formatProvider));
+        }
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte unsigned integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer, ulong value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer, ulong value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        WriteNoAlloc(writer, value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, without allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteNoAlloc(this TextWriter writer,
+        ulong value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        int digitCount = value.CountDigits();
+        Span<char> buffer = stackalloc char[System.Math.Max(digitCount, 1000)];
+        if (value.TryFormat(buffer, out int charsWritten, format, formatProvider))
+        {
+            Span<char> truncated = buffer[..charsWritten];
+            for (var index = 0; index < truncated.Length; index++)
+            {
+                writer.Write(truncated[index]);
+            }
+        }
+        else
+        {
+            writer.Write(value.ToString(format.ToString(), formatProvider));
+        }
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer, int value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer, int value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer, int value, ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteNoAlloc(value, format, formatProvider);
+        writer.WriteLine();
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer, uint value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer, uint value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 4-byte unsigned integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 4-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer,
+        uint value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteNoAlloc(value, format, formatProvider);
+        writer.WriteLine();
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer, long value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer, long value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte signed integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    public static void WriteLineNoAlloc(this TextWriter writer,
+        long value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteNoAlloc(value, format, formatProvider);
+        writer.WriteLine();
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte unsigned integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer, ulong value)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, "N0".AsSpan(), CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer, ulong value, ReadOnlySpan<char> format)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteLineNoAlloc(value, format, CultureInfo.CurrentCulture);
+    }
+
+    /// <summary>
+    ///     Writes the text representation of a 8-byte signed integer to the text stream, followed by a line terminator, without
+    ///     allocating a string.
+    /// </summary>
+    /// <param name="writer">The <see cref="TextWriter" /> to write to.</param>
+    /// <param name="value">The 8-byte unsigned integer to write.</param>
+    /// <param name="format">A standard or custom numeric format string.</param>
+    /// <param name="formatProvider">An object that supplies culture-specific formatting information.</param>
+    /// <remarks>This method may still allocate if the integer is too large to fit in a stack-allocated buffer.</remarks>
+    /// <exception cref="ArgumentNullException"><paramref name="writer" /> is <see langword="null" />.</exception>
+    /// <exception cref="ObjectDisposedException">The <see cref="TextWriter" /> is closed.</exception>
+    /// <exception cref="IOException">An I/O error occurs.</exception>
+    [CLSCompliant(false)]
+    public static void WriteLineNoAlloc(this TextWriter writer,
+        ulong value,
+        ReadOnlySpan<char> format,
+        IFormatProvider? formatProvider)
+    {
+#if NET6_0_OR_GREATER
+        ArgumentNullException.ThrowIfNull(writer);
+#else
+        if (writer is null)
+        {
+            throw new ArgumentNullException(nameof(writer));
+        }
+#endif
+
+        writer.WriteNoAlloc(value, format, formatProvider);
+        writer.WriteLine();
+    }
+}