const std = @import("std");
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const Tag = std.meta.Tag;

const Foo = union {
    float: f64,
    int: i32,
};

test "basic unions" {
    var foo = Foo{ .int = 1 };
    try expect(foo.int == 1);
    foo = Foo{ .float = 12.34 };
    try expect(foo.float == 12.34);
}

test "init union with runtime value" {
    var foo: Foo = undefined;

    setFloat(&foo, 12.34);
    try expect(foo.float == 12.34);

    setInt(&foo, 42);
    try expect(foo.int == 42);
}

fn setFloat(foo: *Foo, x: f64) void {
    foo.* = Foo{ .float = x };
}

fn setInt(foo: *Foo, x: i32) void {
    foo.* = Foo{ .int = x };
}