How to resolve dangling const ref

Question

The following short program

#include <vector>
#include <iostream>

std::vector<int> someNums()
{
    return {3, 5, 7, 11};
}

class Woop
{
public:
    Woop(const std::vector<int>& nums) : numbers(nums) {}
    void report()
    {
        for (int i : numbers)
            std::cout << i << ' ';
        std::cout << '\n';
    }
private:
    const std::vector<int>& numbers;
};

int main()
{
    Woop woop(someNums());
    woop.report();
}

has a dangling reference problem, that no compiler seems to warn about. The issue is that temporaries can be bound to const-refs, which you may then keep around. The question then is; Is there a method of avoiding getting into this problem? Preferably one that does not involve sacrificing const correctness, or always making copies of big objects.

Answer 1

One way to make your class less vulnerable could be to add a deleted constructor that takes a right-ref. This would stop your class instance from making bindings to temporaries.

Woop(std::vector<int>&& nums)  =delete;

This deleted constructor would actually make the O/P code not compile, which may be the behaviour you are looking for?