How to direct-initialize a derived class with an abstract base?

Without the virtual method, the make_unique line in main compiles ok. But I’m lost as to how to direct-initialize a Derived like this when it’s there. Is this possible?

struct Base
{
    virtual void method();
};
struct Derived : public Base
{
    int i;
};

int main() {
    Base base{}; // this works
    make_unique<Derived>(Base{}, 3); // this doesn't compile unless the virtual method is removed
}

I don’t see any mention of virtual methods in the "Direct initilization" page: https://en.cppreference.com/w/cpp/language/direct_initialization

>Solution :

With the virtual method, your Derived class is not an aggregate anymore, so this form of initialization can’t be done.

From cppreference:

An aggregate is one of the following types:

• array type
• class type (typically, struct or union), that has
  • no user-declared constructors
    (until C++11)
  • no user-provided, inherited, or explicit constructors
    (since C++11)
    (until C++20)
  • no user-declared or inherited constructors
    (since C++20)
  • no private or protected [direct (since C++17)] non-static data members
  • no base classes
    (until C++17)
  • no virtual base classes (since C++17)
  • no private or protected direct base classes
    (since C++17)
  • no virtual member functions
  • no default member initializers
    (since C++11)
    (until C++14)