# System.Text.RegularExpressions

``` diff
 namespace System.Text.RegularExpressions {
     [NullableAttribute((byte)0)]
     [NullableContextAttribute((byte)1)]
     public class Regex : ISerializable {
+        [NullableContextAttribute((byte)0)]
+        public int Count(ReadOnlySpan<char> input, int startat);
+        [NullableContextAttribute((byte)0)]
+        public Regex.ValueMatchEnumerator EnumerateMatches(ReadOnlySpan<char> input, int startat);
+        [NullableContextAttribute((byte)0)]
+        public bool IsMatch(ReadOnlySpan<char> input, int startat);
     }
 }
```

