https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71945
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Simpler reproducer which fails the assertion with trunk when the ref count
overflows to INT_MIN, but which passes with my local patches:
#include <memory>
#include <cassert>
#include <climits>
int main()
{
std::shared_ptr<int> p(new int(0));
std::shared_ptr<int> p2;
long count = p.use_count();
while (count < (long)(UINT_MAX))
{
new (&p2) std::shared_ptr<int>(p);
++count;
assert(p.use_count() == count);
}
return *p;
}
And if I change it to make one more copy:
while (count < (long)(UINT_MAX + 1L))
Then the counter no longer overflows, we trap instead:
Illegal instruction (core dumped)
