> compile with -Wreturn-type if you want to avoid such things...

Isn't -Wreturn-type enabled by default in both gcc and clang atleast for c++?

probably - i guess then i meant -Werror=return-type

C on the other hand puts an implicit `return 0` at the end, but only on the main function for some reason. Very weird.

C++ also special-cases the `main` function. Probably because `main` is the interface to the OS so it gets special language treatment.

In C++ you're not allowed to call main yourself, so that the compiler can call the global constructors at the start of main.

Which also exist as C extensions, in some compilers.

In C. In C++ it's an error to not return, as it should be.

.... The blog post literally demonstrates that it is not. Feel free to repro on your own machine.

The main function in the blog post returns at the end of all control paths. Firstly because main has an implicit "return 0" at the end and secondly because no control paths end. It doesn't jump to unreachable because it lacks a return - it jumps there because that's how this implementation has chosen to compile UB, despite the presence of all necessary returns.