I'm reading A tour of C++ (for the second time). I'm also busy working on my application. What I'm noticing is that I have no clue about code style, build systems or anything else outside of that book. If I don't know about it, you can bet that it is hacked together.

I'm mentioning both C++ versions because I've noticed that C++20 features aren't complete, and some features are not well received either (e.g. modules). So I'm doubting if I should learn C++20 for now.

So do you know of any good example projects that show some good stylistic sense C++17/C++20? And I know that people code differently, but trust me, they aren't coding it like I am right now (e.g. .cpp files only, a hacked together build with Meson and benchmark code that have 10ms of test setup bias -- I just discovered that).