pub fn eval(&self, platform: &Platform) -> EnabledTernary {
        let mut res = EnabledTernary::Disabled;
        for spec in self.specs.iter() {
            let matches = spec.eval(platform);
            // Short-circuit evaluation if possible.
            if matches == Some(true) {
                return EnabledTernary::Enabled;
            }
            res = res | EnabledTernary::new(matches);
        }
        res
    }
Runs this evaluator against the given platform.
guppy/src/platform/platform_eval.rs