Trait Cost

pub trait Cost {
    // Required methods
    fn identity() -> Self;
    fn unit() -> Self;
    fn combine(self, other: &Self) -> Self;
}

Requirements for a type to be usable as a cost by a CostModel.

Required Methods

fn identity() -> Self

An identity element, usually zero.

fn unit() -> Self

The default cost for a node with no children, usually one.

fn combine(self, other: &Self) -> Self

A binary operation to combine costs, usually addition. This operation must NOT overflow or panic when given large values!

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl Cost for f32

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for f64

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for i8

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for i16

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for i32

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for i64

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for i128

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for isize

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for u8

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for u16

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for u32

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for u64

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for u128

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for usize

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for BigInt

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

impl Cost for BigRational

fn identity() -> Self

fn unit() -> Self

fn combine(self, other: &Self) -> Self

Implementors

impl Cost for OrderedFloat<f32>

impl Cost for OrderedFloat<f64>