Advanced C++ GUIDE

Much, if not most of software written today is still written in C++ and this has been the case for many, many years.
Not only is C++ popular, it is also a very relevant language. If you go to GitHub you will see that there are a huge number of active C++ repositories and C++ is also extremely active on stack overflow.
There are many, many leading software titles written entirely or partly in C++. These include the Windows, Linux and Mac OSX operating systems!
Many of the Adobe products such as Photoshop and Illustrator, the mySQL and MongoDB database engines, and many many more are written in C++.