You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mod.rs
    path of file: ./repos/irisia-gui/irisia-macros/src/expr/conditional
    
    the code of the file until where you have to start completion: use quote::ToTokens;

use super::{Codegen, StateExpr, StateIf, StateMatch};

pub mod state_if;
pub mod state_match;

pub enum StateCondition
    
    pub fn arms(&self) -> impl Iterator<Item = &[StateExpr<T>]> {
        enum Branch<T, U> {
            T(T),
            U(U),
        }

        let mut iter = match self {
            Self::If(i) => Branch::T(i.arms()),
            Self::Match(m) => Branch::U(m.arms()),
        };

        std::iter::from_fn(move || match &mut iter {
            Branch::T(i) => i.next().map(|block| &*block.stmts),
            Branch::U(m) => m.next().map(|expr| std::array::from_ref(expr) as _),
        })
    }