# System.Buffers

``` diff
 namespace System.Buffers {
     public static class BuffersExtensions {
-        public static SequencePosition? PositionOf<T>(this in ReadOnlySequence<T> source, T value) where T : IEquatable<T>;
+        public static SequencePosition? PositionOf<T>(this in ReadOnlySequence<T> source, T value) where T : IEquatable<T>?;
     }
     public ref struct SequenceReader<T> where T : struct {
+        public bool TryReadExact(int count, out ReadOnlySequence<T> sequence);
     }
     public readonly struct StandardFormat : IEquatable<StandardFormat> {
-        public static StandardFormat Parse(ReadOnlySpan<char> format);
+        public static StandardFormat Parse([StringSyntaxAttribute("NumericFormat")] ReadOnlySpan<char> format);
-        public static StandardFormat Parse(string? format);
+        public static StandardFormat Parse([StringSyntaxAttribute("NumericFormat")] string? format);
-        public static bool TryParse(ReadOnlySpan<char> format, out StandardFormat result);
+        public static bool TryParse([StringSyntaxAttribute("NumericFormat")] ReadOnlySpan<char> format, out StandardFormat result);
     }
 }
```

