Struct Budget 

pub struct Budget { /* private fields */ }

A slice’s remaining allowance.

The contract is one call: Budget::spend returns false when the caller should stop. It is not an error and it is not something to report. A maintenance pass that runs out of budget has done part of its work and will be back on the next turn, which is a hundred nanoseconds away.

Implementations

impl Budget

pub const fn new(units: u32) -> Budget

A budget of units.

pub const fn standard() -> Budget

A budget of MAINTENANCE_UNITS.

pub const fn none() -> Budget

A budget of nothing, which is what a turn hands to an engine that has asked not to be given a slice.

pub const fn spend(&mut self, units: u32) -> bool

Charge units and say whether there is anything left to do after it.

The charge always goes through, even when it takes the budget past the end. Refusing it would mean the caller has to ask before every item and then do the item anyway, which is two branches for the same answer.

pub const fn left(&self) -> u32

What is left.

pub const fn spent(&self) -> u32

What has gone, which is what a counter reports rather than what the slice decides on.

pub const fn is_spent(&self) -> bool

Whether there is any allowance at all.

Trait Implementations

impl Clone for Budget

fn clone(&self) -> Budget

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Budget

impl Debug for Budget

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

Formats the value using the given formatter.

impl Default for Budget

fn default() -> Budget

Returns the “default value” for a type.

impl Eq for Budget

impl PartialEq for Budget

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

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Budget