I like this style in other languages, but unfortunately it's really hard to write this style in C, most of his examples with functions would be pretty inefficie

I like this style in other languages, but unfortunately it's really hard to write this style in C, most of his examples with functions would be pretty inefficient, or at least have somewhat confusing lifetimes. For instance the functions returning a string on the stack which at a glance seem inefficient. I think modern C++ compilers might be able to use move semantics for the examples returning a string, but im not entirely sure and I personally don't like relying on compiler optimisations