Struct Arm
pub struct Arm {
pub attrs: Vec<Attribute>,
pub pat: Pat,
pub guard: Option<(If, Box<Expr>)>,
pub fat_arrow_token: FatArrow,
pub body: Box<Expr>,
pub comma: Option<Comma>,
}Iterator<Item = &Expr>
node: &Arm
node.guard
.as_slice()
.iter()
.map(|(_, expr)| expr.as_ref())
.chain([node.body.as_ref()])Iterator<Item = &mut Expr>
node: &mut Arm
node.guard
.as_mut_slice()
.iter_mut()
.map(|(_, expr)| expr.as_mut())
.chain([node.body.as_mut()])