| 1 | const std = @import("std"); |
| 2 | const assert = std.debug.assert; |
| 3 | const expectEqual = std.testing.expectEqual; |
| 4 | |
| 5 | const PackedStruct = packed struct(u8) { |
| 6 | lo: u4, |
| 7 | hi: u4, |
| 8 | }; |
| 9 | |
| 10 | test "convert to and from backing integer" { |
| 11 | const original: PackedStruct = .{ .lo = 0b1100, .hi = 0b0101 }; |
| 12 | |
| 13 | const backing_int = @backingInt(original); |
| 14 | comptime assert(@TypeOf(backing_int) == u8); |
| 15 | try expectEqual(0b0101_1100, backing_int); |
| 16 | |
| 17 | const reconstructed: PackedStruct = @fromBackingInt(backing_int); |
| 18 | try expectEqual(original, reconstructed); |
| 19 | } |
| 20 | |
| 21 | // test |