A trait for implementing arbitrary return types in the
The C-main function only supports returning integers.
So, every type implementing the
Termination trait has to be converted
to an integer.
The default implementations are returning
libc::EXIT_SUCCESS to indicate
a successful execution. In case of a failure,
libc::EXIT_FAILURE is returned.
Because different runtimes have different specifications on the return value
main function, this trait is likely to be available only on
standard library’s runtime for convenience. Other runtimes are not required
to provide similar functionality.