const expect = @import("std").testing.expect; const builtin = @import("builtin"); const FormValue = union(enum) { One: void, Two: bool, }; fn foo(id: u64) !FormValue { return switch (id) { 2 => FormValue{ .Two = true }, 1 => FormValue{ .One = {} }, else => return error.Whatever, }; } test "switch prong implicit cast" { if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; const result = switch (foo(2) catch unreachable) { FormValue.One => false, FormValue.Two => |x| x, }; try expect(result); }