Enum Select 

pub enum Select {
    Initial,
    At(usize),
    Current,
}

Select a snapshot in a snaplog.

If a snaplog has not yet be mutated then Select::Current == Select::Initial == Select::At(0).

Examples

let mut snaplog = Snaplog::try_from_history((0..=10).map(|n| n * 2))?;

assert_eq!(snaplog[Select::Initial], 0);
assert_eq!(snaplog[Select::At(0)],   0);
assert_eq!(snaplog[Select::At(1)],   2);
assert_eq!(snaplog[Select::At(9)],   18);
assert_eq!(snaplog[Select::At(10)],  20);
assert_eq!(snaplog[Select::Current], 20);

Variants

Initial

Select the initial snapshot before all changes.

At(usize)

Select the snapshot after n changes.

Current

Select the current snapshot after all changes.

Trait Implementations

impl Clone for Select

fn clone(&self) -> Select

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Select

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Index<Select> for Snaplog<T>

type Output = T

The returned type after indexing.

fn index(&self, index: Select) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T: IntoScoped> Index<Select> for Snaplog<T>

type Output = <T as IntoScoped>::Scope

The returned type after indexing.

fn index(&self, index: Select) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T> IndexMut<Select> for Snaplog<T>

fn index_mut(&mut self, index: Select) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl<T: IntoScoped> IndexMut<Select> for Snaplog<T>

fn index_mut(&mut self, index: Select) -> &mut Self::Output

Performs the mutable indexing (container[index]) operation.

impl Copy for Select