When is your "Mastering the C++ STL" course coming out?"

Hi Mosh! I have finished “The Ultimate C++ Series” course of yours. In the end of the the 3rd part of these series, you said that you’ve got a course called “Mastering the C++ STL”. So, when are you planning to create this course?
What is the roadmap for us after learning the C++ STL?

I see there’s been no reply to this question for quite some time. I too would like to know when the Mastering C++ STL course will be available or if it is available and I cannot find it. Thank you.