public class PrimitiveInRecord {
    record Reading(double celsius) {}

    static String classify(Object o) {
        return switch (o) {
            case Reading(int whole) -> "whole degrees: " + whole;     // double component matched against an int pattern
            case Reading(double d) -> "fractional: " + d;
            default -> "not a reading";
        };
    }

    public static void main(String[] args) {
        System.out.println(classify(new Reading(21.0)));
        System.out.println(classify(new Reading(21.5)));
        System.out.println(classify("x"));
    }
}