# System.Text

``` diff
 namespace System.Text {
-    public readonly struct Rune : IComparable, IComparable<Rune>, IEquatable<Rune> {
+    public readonly struct Rune : IComparable, IComparable<Rune>, IEquatable<Rune>, IFormattable, ISpanFormattable {
+        string System.IFormattable.ToString(string format, IFormatProvider formatProvider);
+        bool System.ISpanFormattable.TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider provider);
     }
 }
```

