fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a Expr<'a>> {
match peel_blocks_with_stmt(expr).kind {
ExprKind::AssignOp(ref op1, target, value) => {
fn subtracts_one<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a Expr<'a>> {
match peel_blocks_with_stmt(expr).kind {
ExprKind::AssignOp(ref op1, target, value) => {