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) error!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..]) catch unreachable) == 3); assert(mem.eql(u8, buf[0..3], "-42")); assert((b.print(buf[0..]) catch unreachable) == 2); assert(mem.eql(u8, buf[0..2], "42")); }