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// https://www.boost.org/doc/libs/1_67_0/doc/html/atomic/usage_examples.html#boost_atomic.usage_examples.example_reference_counters
#include <boost/intrusive_ptr.hpp>
#include <boost/atomic.hpp>
class X
{
public:
typedef boost::intrusive_ptr<X> pointer;
X() : refcount_(0) {}
private:
mutable boost::atomic<int> refcount_;
friend void intrusive_ptr_add_ref(const X *x)
{
x->refcount_.fetch_add(1, boost::memory_order_relaxed);
}
friend void intrusive_ptr_release(const X *x)
{
if (x->refcount_.fetch_sub(1, boost::memory_order_release) == 1)
{
boost::atomic_thread_fence(boost::memory_order_acquire);
delete x;
}
}
};
int main()
{
X::pointer x = new X;
}
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