mirror of
https://codeberg.org/ziglang/zig.git
synced 2026-04-26 13:01:34 +03:00
Matthew Lugg
4f7344dec0
Unions with no fields are now "uninstantiable" types, which work like `noreturn` in that values of this type cannot exist. Enums with no fields are different because they are currently considered `extern` types, though https://github.com/ziglang/zig/issues/19855 will change this in the future.
82 lines
2.8 KiB
Zig
82 lines
2.8 KiB
Zig
const EnumInferred = enum {};
|
|
const EnumExplicit = enum(u8) {};
|
|
const EnumNonexhaustive = enum(u8) { _ };
|
|
|
|
const U0 = union {};
|
|
const U1 = union(enum) {};
|
|
const U2 = union(enum(u8)) {};
|
|
const U3 = union(EnumInferred) {};
|
|
const U4 = union(EnumExplicit) {};
|
|
const U5 = union(EnumNonexhaustive) {};
|
|
|
|
export fn init0() void {
|
|
_ = @as(U0, undefined);
|
|
}
|
|
export fn init1() void {
|
|
_ = @as(U1, undefined);
|
|
}
|
|
export fn init2() void {
|
|
_ = @as(U2, undefined);
|
|
}
|
|
export fn init3() void {
|
|
_ = @as(U3, undefined);
|
|
}
|
|
export fn init4() void {
|
|
_ = @as(U4, undefined);
|
|
}
|
|
export fn init5() void {
|
|
_ = @as(U5, undefined);
|
|
}
|
|
|
|
export fn deref0(ptr: *const U0) void {
|
|
_ = ptr.*;
|
|
}
|
|
export fn deref1(ptr: *const U1) void {
|
|
_ = ptr.*;
|
|
}
|
|
export fn deref2(ptr: *const U2) void {
|
|
_ = ptr.*;
|
|
}
|
|
export fn deref3(ptr: *const U3) void {
|
|
_ = ptr.*;
|
|
}
|
|
export fn deref4(ptr: *const U4) void {
|
|
_ = ptr.*;
|
|
}
|
|
export fn deref5(ptr: *const U5) void {
|
|
_ = ptr.*;
|
|
}
|
|
|
|
// error
|
|
//
|
|
// :13:17: error: expected type 'initialize_empty_union.U0', found '@TypeOf(undefined)'
|
|
// :13:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U0'
|
|
// :5:12: note: union declared here
|
|
// :16:17: error: expected type 'initialize_empty_union.U1', found '@TypeOf(undefined)'
|
|
// :16:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U1'
|
|
// :6:12: note: union declared here
|
|
// :19:17: error: expected type 'initialize_empty_union.U2', found '@TypeOf(undefined)'
|
|
// :19:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U2'
|
|
// :7:12: note: union declared here
|
|
// :22:17: error: expected type 'initialize_empty_union.U3', found '@TypeOf(undefined)'
|
|
// :22:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U3'
|
|
// :8:12: note: union declared here
|
|
// :25:17: error: expected type 'initialize_empty_union.U4', found '@TypeOf(undefined)'
|
|
// :25:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U4'
|
|
// :9:12: note: union declared here
|
|
// :28:17: error: expected type 'initialize_empty_union.U5', found '@TypeOf(undefined)'
|
|
// :28:17: note: cannot coerce to uninstantiable type 'initialize_empty_union.U5'
|
|
// :10:12: note: union declared here
|
|
// :32:12: error: cannot load uninstantiable type 'initialize_empty_union.U0'
|
|
// :5:12: note: union declared here
|
|
// :35:12: error: cannot load uninstantiable type 'initialize_empty_union.U1'
|
|
// :6:12: note: union declared here
|
|
// :38:12: error: cannot load uninstantiable type 'initialize_empty_union.U2'
|
|
// :7:12: note: union declared here
|
|
// :41:12: error: cannot load uninstantiable type 'initialize_empty_union.U3'
|
|
// :8:12: note: union declared here
|
|
// :44:12: error: cannot load uninstantiable type 'initialize_empty_union.U4'
|
|
// :9:12: note: union declared here
|
|
// :47:12: error: cannot load uninstantiable type 'initialize_empty_union.U5'
|
|
// :10:12: note: union declared here
|