Inline array of struct assignment

    [System.Runtime.CompilerServices.InlineArray(10)]
    public struct Buffer10<T>
    {
        private T _element0;
    }

 public Buffer10<Header> Headers { get; set; }

    public void AddHeader(Header header)
    {
        Headers[HeadersCount++] = header;
    }

Error CS0131 : The left-hand side of an assignment must be a variable, property or indexer