test.cpp

#include <exception>
#ifdef NDEBUG
#undef NDEBUG
#endif
#include <cassert>

int main() {
    std::exception_ptr p2;
    try {
        throw 42;
    } catch (...) {
        auto p = std::current_exception();
        p2 = std::current_exception();
        assert(p == p2);
    }
}