| author |  Justus Klausecker <justus@klausecker.de> 2025-08-17 18:35:12+02:00 |
| committer |  Andrew Kelley <andrew@ziglang.org> 2025-08-17 19:17:02-07:00 |
| log | cf90a5e451fc170738966a0a1a06c2dd5cddc066 |
| tree | d8a3faa37749d7059111aa6f4b47af897691fbbb |
| parent | c315f2bc2eacc33e2a6e0fcb5b775e20aa506aa7 |
langref: add documentation for unions with inferred tag and explicit tag values
2 files changed, 24 insertions(+), 0 deletions(-)
doc/langref.html.in+7
| ... | @@ -2469,6 +2469,13 @@ or | ... | @@ -2469,6 +2469,13 @@ or |
| 2469 | </p> | 2469 | </p> |
| 2470 | {#code|test_union_method.zig#} | 2470 | {#code|test_union_method.zig#} |
| 2471 | 2471 | ||
| 2472 | <p> | ||
| 2473 | Unions with inferred enum tag types can also assign ordinal values to their inferred tag. | ||
| 2474 | This requires the tag to specify an explicit integer type. | ||
| 2475 | {#link|@intFromEnum#} can be used to access the ordinal value corresponding to the active field. | ||
| 2476 | </p> | ||
| 2477 | {#code|test_tagged_union_with_tag_values.zig#} | ||
| 2478 | |||
| 2472 | <p> | 2479 | <p> |
| 2473 | {#link|@tagName#} can be used to return a {#link|comptime#} | 2480 | {#link|@tagName#} can be used to return a {#link|comptime#} |
| 2474 | {#syntax#}[:0]const u8{#endsyntax#} value representing the field name: | 2481 | {#syntax#}[:0]const u8{#endsyntax#} value representing the field name: |
doc/langref/test_tagged_union_with_tag_values.zig created+17
| ... | @@ -0,0 +1,17 @@ | ||
| 1 | const std = @import("std"); | ||
| 2 | const expect = std.testing.expect; | ||
| 3 | |||
| 4 | const Tagged = union(enum(u32)) { | ||
| 5 | int: i64 = 123, | ||
| 6 | boolean: bool = 67, | ||
| 7 | }; | ||
| 8 | |||
| 9 | test "tag values" { | ||
| 10 | const int: Tagged = .{ .int = -40 }; | ||
| 11 | try expect(@intFromEnum(int) == 123); | ||
| 12 | |||
| 13 | const boolean: Tagged = .{ .boolean = false }; | ||
| 14 | try expect(@intFromEnum(boolean) == 67); | ||
| 15 | } | ||
| 16 | |||
| 17 | // test | ||