private Utf16SharedString trimResult(ReadOnlySpan <char> trimedSpan)
        {
            if (trimedSpan.IsEmpty)
            {
                return(Empty);
            }
            int startIndex = RawString.IndexOf(trimedSpan[0]);

            return(new Utf16SharedString(new string(trimedSpan.ToArray()), sliceSpan(startIndex, trimedSpan.Length)));
        }
 public int IndexOf(string value, int startIndex, int count)
 {
     return(RawString.IndexOf(value, startIndex, count));
 }
 public int IndexOf(string value, int startIndex)
 {
     return(RawString.IndexOf(value, startIndex));
 }
 public int IndexOf(string value)
 {
     return(RawString.IndexOf(value));
 }