Struct contrail::storage::Backtrackable

pub struct Backtrackable;

Objects stored on the trail in backtrackable memory.

Instead of using Backtrackable directly, it's often easier to use the type definitions BacktrackableValue and BacktrackableArray.

Examples

use contrail::{BacktrackableValue, TrailBuilder};

let mut builder = TrailBuilder::new();
let backtrackable_counter = BacktrackableValue::new(&mut builder, 0);
let mut trail = builder.finish();

assert_eq!(backtrackable_counter.get(&trail), 0);

trail.new_level();

backtrackable_counter.update(&mut trail, |x| x + 1);

assert_eq!(backtrackable_counter.get(&trail), 1);

trail.backtrack();

assert_eq!(backtrackable_counter.get(&trail), 0);

Trait Implementations

impl Clone for Backtrackable

fn clone(&self) -> Backtrackable

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Backtrackable

impl Debug for Backtrackable

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

Formats the value using the given formatter.

impl Default for Backtrackable

fn default() -> Backtrackable

Returns the "default value" for a type.

impl Eq for Backtrackable

impl Hash for Backtrackable

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl Ord for Backtrackable

fn cmp(&self, other: &Backtrackable) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<Backtrackable> for Backtrackable

fn eq(&self, other: &Backtrackable) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<Backtrackable> for Backtrackable

fn partial_cmp(&self, other: &Backtrackable) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StorageMode for Backtrackable

fn builder_mut(builder: &mut TrailBuilder) -> &mut MemoryBuilder

Returns the associated MemoryBuilder from a TrailBuilder.

fn memory(trail: &Trail) -> &Memory

Returns the associated Memory from a Trail.

fn memory_mut(trail: &mut Trail) -> &mut Memory

Returns the associated Memory from a Trail mutably.

impl StructuralEq for Backtrackable

impl StructuralPartialEq for Backtrackable