#include <vector>
template<typename T>
struct node {
    void func_ptr_call(void (*visitFunc)()) {
        visitFunc();
    }
    
    std::vector<int> toVector() {
        std::vector<int> v;
        func_ptr_call([&]() {
            v.push_back(0);
        });
        return v;
    }
};
 
 
int main()
{
    node<int> n;
    n.toVector();
}