On Saturday, 17 July 2021 at 20:49:58 UTC, someone wrote:
The following gives me a compiler error when I add the second parameter:is not an lvalue and cannot be modified```d public bool add( ref classTickerID robjTickerID,ref classExchanges robjExchanges = null /// needing this optional) { } ```If I take out the null then the parameter is assumed mandatory of course.
Just remove `ref`, because in D clasess themselves are references.