zig/test/cases/enum_with_members.zig
Andrew Kelley 0ad1239522 rework enums and unions and their relationship to each other
* @enumTagName renamed to @tagName and it works on enums and
   union-enums
 * Remove the EnumTag type. Now there is only enum and union,
   and the tag type of a union is always an enum.
 * unions support specifying the tag enum type, and they support
   inferring an enum tag type.
 * Enums no longer support field types but they do support
   setting the tag values. Likewise union-enums when inferring
   an enum tag type support setting the tag values.
 * It is now an error for enums and unions to have 0 fields.
 * switch statements support union-enums

closes #618
2017-12-03 20:43:56 -05:00

28 lines
702 B
Zig

const assert = @import("std").debug.assert;
const mem = @import("std").mem;
const fmt = @import("std").fmt;
const ET = union(enum) {
SINT: i32,
UINT: u32,
pub fn print(a: &const ET, buf: []u8) -> %usize {
return switch (*a) {
ET.SINT => |x| { fmt.formatIntBuf(buf, x, 10, false, 0) },
ET.UINT => |x| { fmt.formatIntBuf(buf, x, 10, false, 0) },
}
}
};
test "enum with members" {
const a = ET { .SINT = -42 };
const b = ET { .UINT = 42 };
var buf: [20]u8 = undefined;
assert(%%a.print(buf[0..]) == 3);
assert(mem.eql(u8, buf[0..3], "-42"));
assert(%%b.print(buf[0..]) == 2);
assert(mem.eql(u8, buf[0..2], "42"));
}