Trait ref_map::OptionRefMap [−][src]
pub trait OptionRefMap<'o, T: 'o> { fn ref_map<U, F>(&'o self, f: F) -> Option<U>
where
F: FnOnce(&'o T) -> U; }
Expand description
Adds the ref_map()
extension method onto Option
.
The ref_map()
method borrows the internal object and passes it
to a closure to be mapped in some way. This allows convenient use
of as_*
type methods or calculations which require the borrowed
internal value.
use ref_map::*; let values = Some(vec![4, 7, 9, 5, 6]); let filtered = values.ref_map(|v| &v[3..]); let answer = &[5, 6]; assert_eq!(filtered, Some(&answer[..]));
See the crate-level documentation for more information.