immer: Segmentation fault with recursive types

I found what appears to be a memory corruption issue with recursive types using box. Below is a minimal reproducer which seg-faults on my machine. I am on clang, MacOS 10.14, and -std=c++14.

#include "immer/vector.hpp"
#include "immer/box.hpp"




//=============================================================================
struct my_type
{
    using container_t = immer::vector<immer::box<my_type>>;
    using func_t = std::function<int(int)>;

    int ival;
    double dval;
    func_t func;
    container_t children;
};




//=============================================================================
int main()
{
    my_type::container_t items = {my_type()};
    return 0;
}