> LLVM's own code, seems to use only the rudimentary features of C++ (primarily, single-inheritance). And this absence of complex C++ features made me feel comf

> LLVM's own code, seems to use only the rudimentary features of C++ (primarily, single-inheritance). And this absence of complex C++ features made me feel comfortable looking at, reading, and understanding the LLVM code. Uh, what parts of LLVM were you reading? Because LLVM uses pretty much every C++14 feature allowed by their coding standard. The fact that you felt like no complex machinery was being used is actually a testament of the powers of abstraction in C++.