docs.rs
pub struct ExprIf { pub attrs: Vec<Attribute>, pub if_token: If, pub cond: Box<Expr>, pub then_branch: Block, pub else_branch: Option<(Else, Box<Expr>)>, }
node: &ExprIf
[node.cond.as_ref()] .into_iter() .chain( node.else_branch .as_ref() .map(|(_, expr)| expr.as_ref()), )
node: &mut ExprIf
[node.cond.as_mut()] .into_iter() .chain( node.else_branch .as_mut() .map(|(_, expr)| expr.as_mut()), )