namespace System { internal static class HexConverter { public enum Casing : uint { Upper = 0, Lower = 8224 } public static ReadOnlySpan<byte> CharToHexLookup { get; } public static void ToCharsBuffer(byte value, Span<char> buffer, int startingIndex = 0, Casing casing = Casing.Upper); public static int FromChar(int c); public static int FromLowerChar(int c); public static bool IsHexLowerChar(int c); } }