Challenge 3: Property, Positional, and Discard Patterns Together — Possible Solution
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Program.cs:

public record Point(int X, int Y);

static string Describe(Point p) => p switch
{
    { X: 0, Y: 0 } => "origin",
    (_, 0) => "on the X axis",
    _ => "elsewhere"
};

Console.WriteLine(Describe(new Point(0, 0)));
Console.WriteLine(Describe(new Point(5, 0)));
Console.WriteLine(Describe(new Point(3, 4)));

Output:

    origin
    on the X axis
    elsewhere

Explanation:
{ X: 0, Y: 0 } is a property pattern, matching only when both named
properties equal the given values -- it catches the (0, 0) case
first. (_, 0) is a positional pattern using the record's own
Deconstruct: it matches any Point whose second deconstructed value
(Y) is 0, regardless of X (the discard _ accepts anything there) --
this is what "on the X axis" means. The final discard _ catches
everything else, like (3, 4). Point (0, 0) matches the FIRST pattern
in the switch even though it would also technically match (_, 0),
since switch expressions test patterns top-to-bottom and stop at the
first match.

WHY THIS WORKS AS AN ANSWER
------------------------------
This combines a property pattern, a positional pattern using the
record's own Deconstruct, and a final discard exactly as the chapter
introduces them, tested against three genuinely different points to
confirm each pattern fires correctly and pattern order is respected.