I read this article (and this https://www.mql5.com/en/forum/335975 and this https://www.mql5.com/en/articles/5) during a bug fix session related to custom indicator buffers, I finally fix it when I realized that only one buffer can set with INDICATOR_DATA flag, otherwise CopyBuffers/GetData returns always -1 except for the first indicator flagged as INDICATOR_DATA.
Why wrapping a simple indicator into a class if it is used later either in a chart or via iCustom?
OOP for OOP's sake, okay.
That's right)))
Very convenient, I recommend it to everyone