Thread: Simple factory pattern

Hello,

how can pass a value to the constructor of the derived structs in this simple factory pattern? thx

Code:

#include <iostream>
#include <memory>
#include <vector>

struct B {
	virtual ~B() = default;
};

struct D1 : B {
	int Val;
	D1(int val) : Val(val) {}
};

struct D2 : B {
	int Val;
	D2(int val) : Val(val) {}
};

template<typename T> std::unique_ptr<B> factory(int val) {
	return std::make_unique<T>(val);
}

int main() {
	std::vector<std::shared_ptr<B>> vec{ factory<D1>(1), factory<D2>(2) };
	for(const auto& v : vec ) std::cout << v->Val << '\n';
}