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+//
+// Now that we've seen how methods work, let's see if we can help
+// our elephants out a bit more with some Elephant methods.
+//
+const std = @import("std");
+
+const Elephant = struct {
+ letter: u8,
+ tail: ?*Elephant = null,
+ visited: bool = false,
+
+ // New Elephant methods!
+ pub fn getTail(self: *Elephant) *Elephant {
+ return self.tail.?; // Remember, this is means "orelse unreachable"
+ }
+
+ pub fn hasTail(self: *Elephant) bool {
+ return (self.tail != null);
+ }
+
+ pub fn visit(self: *Elephant) void {
+ self.visited = true;
+ }
+
+ pub fn print(self: *Elephant) void {
+ // Prints elephant letter and [v]isited
+ var v: u8 = if (self.visited) 'v' else ' ';
+ std.debug.print("{u}{u} ", .{ self.letter, v });
+ }
+};
+
+pub fn main() void {
+ var elephantA = Elephant{ .letter = 'A' };
+ var elephantB = Elephant{ .letter = 'B' };
+ var elephantC = Elephant{ .letter = 'C' };
+
+ // Link the elephants so that each tail "points" to the next.
+ elephantA.tail = &elephantB;
+ elephantB.tail = &elephantC;
+
+ visitElephants(&elephantA);
+
+ std.debug.print("\n", .{});
+}
+
+// This function visits all elephants once, starting with the
+// first elephant and following the tails to the next elephant.
+fn visitElephants(first_elephant: *Elephant) void {
+ var e = first_elephant;
+
+ while (true) {
+ e.print();
+ e.visit();
+
+ // Get the next elephant or stop.
+ if (e.hasTail()) {
+ e = e.???; // Which method do we want here?
+ } else {
+ break;
+ }
+ }
+}
+
+// Bonus: Zig's enums can also have methods! Can you find
+// one in the wild? If you can, mention it along with your
+// name or alias in a comment below this one and make a
+// pull request on GitHub for a piece of eternal Ziglings
+// glory. The first five (5) PRs will be accepted!
+//
+// 1) drforester - I found one in the Zig source:
+// https://github.com/ziglang/zig/blob/041212a41cfaf029dc3eb9740467b721c76f406c/src/Compilation.zig#L2495
+//
+// 2) bbuccianti - I found one!
+// https://github.com/ziglang/zig/blob/master/lib/std/debug.zig#L477
+//