`std::vector<T&>`; because, why not?

vector_ref.cpp

#include <iostream>
#include <vector>

namespace std {

template<class T>
class vector<T&> {
public:
    vector() : data(new T*[capacity]) {}

    size_t size() const {
        return d_size;
    }

    void push_back(T& x) {
        if (d_size == capacity) {
            capacity <<= 1;
            T** old_data = data;
            data = new T*[capacity];
            for (size_t i = 0; i < d_size; ++i)
                data[i] = old_data[i];
            delete [] old_data;
        }
        data[d_size] = &x;
        ++d_size;
    }

    T& operator[](size_t i) {
        return *data[i];
    }

    const T& operator[](size_t i) const {
        return *data[i];
    }

    ~vector() {
        delete [] data;
    }

private:
    size_t d_size = 0;
    size_t capacity = 2;
    T** data;
};

}

int main()
{
    std::vector<int&> v;
    int a = 10;
    for (auto i = 0; i < 10000; ++i)
        v.push_back(a);
    v[10] = 100;
    std::cout << v.size() << '\n';
    std::cout << v[0] << '\n';
    return 0;
}