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use std::rc::Rc;
use std::sync::Arc;

pub trait Formula<T> {
    type Error: std::error::Error;

    /// Returns a boolean value indicating whether or not the value satisfies some criteria.
    fn satisfied_by(&self, value: &T) -> Result<bool, Self::Error>;
}

impl<T, F: Formula<T> + ?Sized> Formula<T> for &'_ F {
    type Error = F::Error;

    fn satisfied_by(&self, value: &T) -> Result<bool, Self::Error> {
        (**self).satisfied_by(value)
    }
}

// TODO remove this definition and use Box inside each of the operators with overloading of constructor
impl<T, F: Formula<T> + ?Sized> Formula<T> for Box<F> {
    type Error = F::Error;

    fn satisfied_by(&self, value: &T) -> Result<bool, Self::Error> {
        (**self).satisfied_by(value)
    }
}

impl<T, F: Formula<T> + ?Sized> Formula<T> for Rc<F> {
    type Error = F::Error;

    fn satisfied_by(&self, value: &T) -> Result<bool, Self::Error> {
        (**self).satisfied_by(value)
    }
}

impl<T, F: Formula<T> + ?Sized> Formula<T> for Arc<F> {
    type Error = F::Error;

    fn satisfied_by(&self, value: &T) -> Result<bool, Self::Error> {
        (**self).satisfied_by(value)
    }
}