shouldNotBeNull

class Foo
{
    this(int i) { this.i = i; }
    override string toString() const
    {
        import std.conv: to;
        return i.to!string;
    }
    int i;
}

shouldNotBeNull(new Foo(4)) ;
shouldEqual(new Foo(5), new Foo(5));
assertFail(shouldEqual(new Foo(5), new Foo(4)));
shouldNotEqual(new Foo(5), new Foo(4)) ;
assertFail(shouldNotEqual(new Foo(5), new Foo(5)));