> If the a C++ file includes any C++ stdlib header it will also also become very large (tens of thousands of lines of gnarly template code for common headers like <vector> or <string>). If the unit of compilation is a crate in Rust it should actually be faster to build than typical C++ projects which often put the implementation for one class into one source file (and each of those source files is expanded to tens of thousands of lines of code after includes are resolved).

> C mostly doesn't suffer from this problem though, since C header typically are only a couple dozen or hundred lines of API declarations.

But then, there's no reason why Rust couldn't be like C. The issue comes from the dependencies and libraries bundled, which is not an issue per se of the language.