Struct ZBI

pub struct ZBI<T>(pub T);

Newtype offering some utility methods for zero-based indices

Tuple Fields

0: T

Implementations

impl ZBI<usize>

pub const fn to_len(&self) -> Option<usize>

If the cardinality of the closed integer interval from 0 to the stored value fits into usize, returns that cardinality as Some variant of Option<usize>. Otherwise (when happens integer overflow), the returned value is None.

Using mathematical notation,

Examples

Base case

use zero_based_index::ZBI;

let zbi = ZBI(2usize);
assert_eq!(zbi.to_len(), Some(3));

Corner case

use zero_based_index::ZBI;

let zbi = ZBI(usize::MAX);
assert_eq!(zbi.to_len(), None);