Trait type_rules::Rule

pub trait Rule<T: ?Sized> {
    fn check(&self, value: &T) -> Result<(), String>;
}

Define a rule for a type

By implementing Rule for a type you define how it will be used to constraint a type T

Example

use type_rules::prelude::*;

struct IsEven();

impl Rule<i32> for IsEven {
    fn check(&self, value: &i32) -> Result<(), String> {
        if value % 2 == 0 {
            Ok(())
        } else {
            Err("Value is not even".into())
        }
    }
}

#[derive(Validator)]
struct MyInteger(#[rule(IsEven())] i32);

Required Methods

fn check(&self, value: &T) -> Result<(), String>

Implementors

impl<'a, T, U> Rule<U> for All<'a, T> where
    U: IntoIterator,
    for<'b> &'b U: IntoIterator<Item = &'b U::Item>,
    T: Rule<<U as IntoIterator>::Item>, 

impl<'a, T, U> Rule<U> for Any<'a, T> where
    U: IntoIterator,
    for<'b> &'b U: IntoIterator<Item = &'b U::Item>,
    T: Rule<<U as IntoIterator>::Item>, 

impl<'a, T, U> Rule<U> for Eval<'a, T> where
    T: Fn(&U) -> bool, 

impl<'a, T, U> Rule<U> for In<'a, T> where
    T: IntoIterator,
    for<'b> &'b T: IntoIterator<Item = &'b T::Item>,
    U: PartialEq<T::Item>, 

impl<'a, T: AsRef<str> + ?Sized> Rule<T> for RegEx<'a>

Available on crate feature regex only.

impl<T> Rule<Vec<T, Global>> for MaxSize

impl<T> Rule<Vec<T, Global>> for MinMaxSize

impl<T> Rule<Vec<T, Global>> for MinSize

impl<T, U, F> Rule<F> for And<T, U> where
    T: Rule<F>,
    U: Rule<F>, 

impl<T, U, F> Rule<F> for Or<T, U> where
    T: Rule<F>,
    U: Rule<F>, 

impl<T, U: Rule<T>> Rule<Option<T>> for Opt<U>

impl<T: PartialOrd<T>> Rule<T> for MaxRange<T>

impl<T: PartialOrd<T>> Rule<T> for MinMaxRange<T>

impl<T: PartialOrd<T>> Rule<T> for MinRange<T>

impl<T: AsRef<str> + ?Sized> Rule<T> for MaxLength

impl<T: AsRef<str> + ?Sized> Rule<T> for MinLength

impl<T: AsRef<str> + ?Sized> Rule<T> for MinMaxLength

impl<T: Validator> Rule<T> for Validate