| 1 | const std = @import("std"); |
| 2 | const expect = std.testing.expect; |
| 3 | |
| 4 | const Variant = union(enum) { |
| 5 | int: i32, |
| 6 | boolean: bool, |
| 7 | |
| 8 | // void can be omitted when inferring enum tag type. |
| 9 | none, |
| 10 | |
| 11 | fn truthy(self: Variant) bool { |
| 12 | return switch (self) { |
| 13 | Variant.int => |x_int| x_int != 0, |
| 14 | Variant.boolean => |x_bool| x_bool, |
| 15 | Variant.none => false, |
| 16 | }; |
| 17 | } |
| 18 | }; |
| 19 | |
| 20 | test "union method" { |
| 21 | var v1: Variant = .{ .int = 1 }; |
| 22 | var v2: Variant = .{ .boolean = false }; |
| 23 | var v3: Variant = .none; |
| 24 | |
| 25 | try expect(v1.truthy()); |
| 26 | try expect(!v2.truthy()); |
| 27 | try expect(!v3.truthy()); |
| 28 | } |
| 29 | |
| 30 | // test |