Trait Convert 

pub trait Convert {
    const BASE: Self;

    // Required method
    fn conversion_factor(&self) -> f64;

    // Provided method
    fn conversion_factor_to(&self, _: impl Into<Unit>) -> Option<f64> { ... }
}

A trait implemented by all Unit, providing the information needed to convert between them.

Required Associated Constants

const BASE: Self

The base unit of this unit.

The base unit is the unit in which conversions to other units of the same quantity are defined. For example, the base unit of length is the meter, and the base unit of volume is the cubic meter. It isn’t particularly important which unit is chosen as the base unit, as long as conversions between each unit and the base unit are correctly defined.

In some cases, the choice of base unit may affect the precision of conversions. For example, metric and customary units often don’t have exact conversions between them. If the base unit is chosen to be a metric unit, then conversions between customary units will be done by converting to the metric base unit, and then to the target customary unit, which is where the precision loss can occur.

Required Methods

fn conversion_factor(&self) -> f64

Returns the conversion factor from &self to Convert::BASE, i.e. the value to multiply a quantity in this unit by, in order to get a quantity in Convert::BASE. If the self unit is the same as this unit, then this function should return 1.0.

For example, if Convert::BASE is the meter, the conversion factor for a centimeter would be 0.01.

Provided Methods

fn conversion_factor_to(&self, _: impl Into<Unit>) -> Option<f64>

Defines the conversion factor from Convert::BASE, to a base unit that Convert::BASE is derived from. Returns None if there is no conversion factor, meaning the two units are unrelated.

For example, Volume is derived from Length units cubed. The base unit for Length is defined to be Length::Meter. So, this function should be manually implemented for Volume, and it should return the value to multiply by to convert from Volume::? to cubic meters.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Convert for Area

const BASE: Self = Area::Are

impl Convert for Length

const BASE: Self = Length::Meter

impl Convert for Mass

const BASE: Self = Mass::Kilogram

impl Convert for Time

const BASE: Self = Time::Second

impl Convert for Volume

const BASE: Self = Volume::Liter