Function max

pub fn max<'a, T, A, B, C, D>(a: A, b: B, c: C) -> Goal<'a, D>
where
    T: PartialOrd + UnifyIn<'a, D> + 'a,
    A: IntoVal<T>,
    B: IntoVal<T>,
    C: IntoVal<T>,
    D: DomainType<'a, T>,

Get the greater of two values according to std::cmp::max.

Example:

use canrun::{unify, util, var, all, Goal};
use canrun::domains::example::I32;
use canrun_basic::max;

let (x, y, z) = (var(), var(), var());
let goal: Goal<I32> = all![
    unify(x, 1),
    unify(y, 2),
    unify(z, 2),
    max(x, y, z),
];
let results: Vec<_> = goal.query((x, y, z)).collect();
assert_eq!(results, vec![(1, 2, 2)]);