[Bug libstdc++/63698] [5 Regression] std::set leaks nodes on assignment

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63698

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This still leaks like a sieve without the second patch:

#include <set>
#include <random>

int main()
{
  std::mt19937 rng;
  std::uniform_int_distribution<int> d;
  std::uniform_int_distribution<int>::param_type p{0, 100};
  std::uniform_int_distribution<int>::param_type x{0, 1000};

  for (int i = 0; i < 10; ++i)
  {
    std::set<int> l, r;
    for (int n = d(rng, p); n > 0; --n)
    {
      int i = d(rng, x);
      l.insert(i);
      r.insert(i);
      l = r;
    }
  }
}