If you're interested in this topic, you may want to check out the "Physically Based Rendering" book[1]. It's basically a college text book (and priced accordingly) but it walks through the steps to build a fully functional (and fairly performant) ray tracing engine in C++. As a bonus, the code is BSD licensed, and up on github[2].
It's been great to go through it so far; I'm re-writing the renderer in a different language to help with the learning, I can't recommend it enough.
These books discuss performant (and sometimes complex) C++ code - in the domain of computer graphics.
http://www.amazon.com/Physically-Based-Rendering-Second-Edit...
http://www.amazon.com/Real-Time-Collision-Detection-Interact...
About how to use the new threading standard: https://www.manning.com/books/c-plus-plus-concurrency-in-act...
It's been great to go through it so far; I'm re-writing the renderer in a different language to help with the learning, I can't recommend it enough.
[1]http://www.amazon.com/Physically-Based-Rendering-Second-Impl... [2] https://github.com/mmp/pbrt-v2
Though, I also feel that that adds to the time of creating these papers. So, by my own view this might be more expensive than it is worth.