I know that doesn't answer your question and to be honest, I am curious about the resources which come up here too, but C++ can be so painful to learn that I wanted to know what drives you into that direction. I mean, there are alternatives like Rust. Do you have a specific project in mind, need it to fulfill some résumé requirements or something completely different?
Any complex or high-performance computing relies on C/C++ pretty heavily still.
It's also a good tool to have in your box for building well-performing cross-platform native apps with Qt.
I say this as one who's probably at the same stage as OP. Know some C, and reasonably comfortable with the basics. Application of C++ is a little more widespread outside of strict embedded environments, however. (Another space I personally want to immerse myself in)
(There are worse but deprecated like MFC. Or on par like wxWidgets.)
I find Rust is a much better language, but there are very few mature libraries right now if you do something outside the scope of what Mozilla is doing. Also very few companies that are working in Rust (AFAIK, if you know some let me know) looking for devs.
If you want to work in a company that is doing any kind of low level code you will either need C or C++ as a foundation. At least to understand existing code. Most companies won't just rewrite everything in Rust, no matter how good the language is.
I really hope Rust replaces C++ for new projects, but it's just too new to tell whether that will happen. I find there's a bit more momentum (and good ideas) than in D, but nobody can predict the future from 2-3 years of language history.
“This Week in Rust” lists explicit job postings. One of the latest companies looking for Rust programmers is a little company you may have heard of: Facebook.
That said, many places are hiring good programmers and putting them on Rust projects, rather than hiring Rust programmers explicitly. There aren’t many pure Rust shops yet, so they need a broader skill set.
I still haven't grasped Rust as much as I'd like, but I have to admit that at least it feels like every part of the language fits nicely together with the others, as opposed to the "messy spaghetti" feel I get from C++ (though this is of course my subjective impression).
There are things I'd like they do, like removing the Python 2 dependency for building from source, or actually writing a spec. But I guess that'll come with time.
I'd like to learn OpenGL programming, and C seems too painfully low level for that, although I won't argue that it is a lot easier to wrap your head around it. However, this days I've been toying with C++14, and the experience (apart from the dependencies, Makefiles, et al. mess, has been pretty smooth with regards to syntax.
Apart from OpenGL (which seems like a neat way to learn some interesting maths and physics), learning C++ helps delve into many big and important existing codebases, especially databases, and other complex systems. Rust may be designed for that but it isn't used so much in the wild.
Moreover, I want to feel badass in a hardcore low-level hacker way after programming so much in high-level dynamically-typed languages, and contribute my one stone to the future grave of JS/Node (let's hope Atwood's law won't work :P).