merlin-utils/unique_resource.h

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2019-12-08 18:55:33 +00:00
#ifndef __unique_resource_h__
#define __unique_resource_h__
#include <utility>
template <class T, class D>
class unique_resource {
public:
typedef T element_type;
typedef D deleter_type;
unique_resource() = default;
unique_resource(const unique_resource &) = delete;
unique_resource(unique_resource &&rhs) {
swap(rhs);
}
unique_resource(T t, D d): _pair(t,d), _active(true)
{}
~unique_resource() {
reset();
}
unique_resource &operator=(const unique_resource &) = delete;
unique_resource &operator=(unique_resource &&rhs) {
if (this != std::addressof(rhs)) {
reset();
swap(rhs);
}
return *this;
}
void swap(unique_resource & rhs) {
if (this != std::addressof(rhs)) {
std::swap(_active, rhs._active);
std::swap(_pair, rhs._pair);
}
}
void reset(T t) {
reset();
_active = true;
_pair.first = t;
}
void reset(T t, D d) {
reset();
_active = true;
_pair = std::make_pair(t, d);
}
void reset() {
if (_active) {
(*_pair.second)(_pair.first);
_active = false;
}
}
T release() {
_active = false;
return _pair.first;;
}
T get() {
return _pair.first;
}
operator bool() const {
return _active;
}
D& get_deleter() {
return _pair.second;
}
const D& get_deleter() const {
return _pair.second;
}
private:
std::pair<T, D> _pair;
bool _active = false;
};
#define MAKE_UNIQUE_RESOURCE(T, D) \
unique_resource<decltype(T), decltype(D) *>(T, D)
template<class T, class D>
unique_resource<T, D> make_unique_resource(T t, D d) {
return unique_resource<T, D>(t, d);
}
#endif