| ... | ... | @@ -6448,14 +6448,37 @@ const U = union(E) { |
| 6448 | 6448 | three, |
| 6449 | 6449 | }; |
| 6450 | 6450 | |
| 6451 | const U2 = union(enum) { |
| 6452 | a: void, |
| 6453 | b: f32, |
| 6454 | |
| 6455 | fn tag(self: U2) usize { |
| 6456 | switch (self) { |
| 6457 | .a => return 1, |
| 6458 | .b => return 2, |
| 6459 | } |
| 6460 | } |
| 6461 | }; |
| 6462 | |
| 6451 | 6463 | test "coercion between unions and enums" { |
| 6452 | 6464 | var u = U{ .two = 12.34 }; |
| 6453 | | var e: E = u; |
| 6465 | var e: E = u; // coerce union to enum |
| 6454 | 6466 | try expect(e == E.two); |
| 6455 | 6467 | |
| 6456 | 6468 | const three = E.three; |
| 6457 | | var another_u: U = three; |
| 6458 | | try expect(another_u == E.three); |
| 6469 | var u_2: U = three; // coerce enum to union |
| 6470 | try expect(u_2 == E.three); |
| 6471 | |
| 6472 | var u_3: U = .three; // coerce enum literal to union |
| 6473 | try expect(u_3 == E.three); |
| 6474 | |
| 6475 | var u_4: U2 = .a; // coerce enum literal to union with inferred enum tag type. |
| 6476 | try expect(u_4.tag() == 1); |
| 6477 | |
| 6478 | // The following example is invalid. |
| 6479 | // error: coercion from enum '@TypeOf(.enum_literal)' to union 'test_coerce_unions_enum.U2' must initialize 'f32' field 'b' |
| 6480 | //var u_5: U2 = .b; |
| 6481 | //try expect(u_5.tag() == 2); |
| 6459 | 6482 | } |
| 6460 | 6483 | {#code_end#} |
| 6461 | 6484 | {#see_also|union|enum#} |
Manlio Perillo <manlio.perillo@gmail.com> 2023-01-24 16:11:38+01:00
Veikka Tuominen <git@vexu.eu> 2023-01-25 17:03:39+02:00