ba549a7d67
If both are used, 'else' handles named members and '_' handles unnamed members. In this case the 'else' prong will be unrolled to an explicit case containing all remaining named values.
44 lines
1.0 KiB
Zig
44 lines
1.0 KiB
Zig
const E = enum(u8) {
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a,
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b,
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_,
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};
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const U = union(E) {
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a: i32,
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b: u32,
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};
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pub export fn entry1() void {
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const e: E = .b;
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switch (e) { // error: switch not handling the tag `b`
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.a => {},
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_ => {},
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}
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}
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pub export fn entry2() void {
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const e: E = .b;
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switch (e) { // error: switch on non-exhaustive enum must include `else` or `_` prong
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.a => {},
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.b => {},
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}
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}
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pub export fn entry3() void {
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const u = U{ .a = 2 };
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switch (u) { // error: `_` prong not allowed when switching on tagged union
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.a => {},
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.b => {},
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_ => {},
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}
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}
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// error
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// backend=stage2
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// target=native
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//
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// :12:5: error: switch must handle all possibilities
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// :3:5: note: unhandled enumeration value: 'b'
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// :1:11: note: enum 'tmp.E' declared here
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// :19:5: error: switch on non-exhaustive enum must include 'else' or '_' prong or both
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// :26:5: error: '_' prong only allowed when switching on non-exhaustive enums
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// :29:9: note: '_' prong here
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// :26:5: note: consider using 'else'
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