use {
crate::{
construct::{
Algebraic, Construct, CtorFn, Decomposition, ElimFn, IntroductionRule, TypeFormer,
visit_self,
},
multiset::Multiset,
reflection::{TermsOfVariousTypes, Type, register, type_of},
scc::StronglyConnectedComponents,
},
core::{marker::PhantomData, num::NonZero},
std::collections::BTreeSet,
};
impl<T: Construct> Construct for PhantomData<T> {
#[inline]
fn register_all_immediate_dependencies(
visited: &mut BTreeSet<Type>,
sccs: &mut StronglyConnectedComponents,
) {
if !visited.insert(type_of::<Self>()) {
return;
}
let () = register::<T>(visited.clone(), sccs);
}
#[inline]
fn type_former() -> TypeFormer<Self> {
TypeFormer::Algebraic(Algebraic {
introduction_rules: vec![IntroductionRule {
arbitrary_fields: |_, _| TermsOfVariousTypes::new(),
call: CtorFn::new(|_terms| Some(PhantomData)),
immediate_dependencies: Multiset::new(),
}],
elimination_rule: ElimFn::new(|_| Decomposition {
ctor_idx: const { NonZero::new(1).unwrap() },
fields: TermsOfVariousTypes::new(),
}),
})
}
#[inline]
fn visit_deep<V: Construct>(&self) -> impl Iterator<Item = V> {
visit_self(self)
}
}