Struct Modifier 

pub struct Modifier { /* private fields */ }

A validated operator and value applied to a roll’s total.

Create one with Modifier::try_new.

Implementations

impl Modifier

pub fn try_new(operator: Operator, value: u32) -> Result<Self, NotationError>

Creates a modifier, checking the value is usable with the operator.

Errors

Returns NotationError::Zero if the operator is Operator::Div and the value is zero, or NotationError::NumberTooLarge if the value exceeds MAX_VALUE.

Examples

use rust_roll::notation::{Modifier, Operator};

let modifier = Modifier::try_new(Operator::Add, 3).unwrap();
assert_eq!(modifier.apply(10), 13);

assert!(Modifier::try_new(Operator::Div, 0).is_err());

pub fn operator(self) -> Operator

The modifier’s operator.

pub fn value(self) -> u32

The modifier’s value.

pub fn apply(self, total: u32) -> u32

Applies the modifier to a total.

The result never goes below zero or above u32::MAX: subtraction stops at zero and addition and multiplication saturate. Division rounds down, following the D&D 5e (2014) rules.

Examples

use rust_roll::notation::{Modifier, Operator};

let halve = Modifier::try_new(Operator::Div, 2).unwrap();
assert_eq!(halve.apply(7), 3);

let minus_five = Modifier::try_new(Operator::Sub, 5).unwrap();
assert_eq!(minus_five.apply(3), 0);

Trait Implementations

impl Clone for Modifier

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Modifier

impl Debug for Modifier

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

Formats the value using the given formatter.

impl Display for Modifier

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

Formats the value using the given formatter.

impl Eq for Modifier

impl PartialEq for Modifier

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Modifier