----- match item_option { Some(item) => {
//Do something with resource
println!("{}", item);
}
None => {}Wouldn't this be better with design by contract by having first() enforce length>0 then turning off assertions if desired for release code? Also OP should have mentioned not matching none is an error otherwise there's no point
If the caller wants to kill the program when its empty, they can just call `.unwrap()` on the option to explicitly opt-in to a runtime check.
I would say very much not, but maybe I'm misunderstanding what you mean, or maybe you're misunderstanding the language?
What I'm getting from your suggestion is
pub fn first(&self) -> &T {
debug_assert!(self.len() > 0);
unsafe { &* self.as_ptr() }
}
What you could do is have a separate `NonEmpty` vector either by construction or by assertion, for which `first` wouldn't be failible (but other operations would be).
> Also OP should have mentioned not matching none is an error otherwise there's no point
That actually is irrelevant to the story OP is telling. They're talking about null-safety, match-completeness is an orthogonal concern (and one they don't really care for here, they just want to operate on a present value).