someone to-be—is used with reference to a position or status a person will have in the future:
- I met my wife-to-be, Elaine, a few months later, and we were married in November.
Cf.: a has-been—said of smb. who is no longer effective in what he does:
- Rocky is now a “has-been,” spending most of his time retelling old boxing stories.
would-be someone—said of smb. intending to be a particular kind of person:
- Bus conductors are having a busy time dissuading would-be passengers from trying to board their buses.