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#ifndef __BTAS_UTIL_OPTIONAL_PTR_H
#define __BTAS_UTIL_OPTIONAL_PTR_H 1
#include <memory>
namespace btas {
/**
optional_ptr<T> functions either as a raw unmanaged pointer
or as a smart pointer of type managed_ptr depending on whether
it is initialized through the set_external method or
the set_managed method
*/
template <typename T, typename managed_ptr = std::unique_ptr<T>>
class optional_ptr
{
public:
using ptr = T*;
optional_ptr() : p_(nullptr) { }
optional_ptr(optional_ptr&& other)
:
p_(other.p_),
up_(std::move(other.up_))
{ }
T&
operator*() const { return *p_; }
ptr
operator->() const { return p_; }
void
set_managed(ptr new_p)
{
up_ = std::move(managed_ptr(new_p));
p_ = up_.get();
}
void
set_external(ptr ext_p)
{
p_ = ext_p;
up_.reset();
}
private:
ptr p_;
managed_ptr up_;
};
} // namespace btas
#endif // __BTAS_UTIL_OPTIONAL_PTR_H
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