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// -*- C++ -*-
/** \file cleanup.h
* \brief Classes to facilitate use of RIAA cleanup.
*/
#ifndef _CLEANUP_H_
#define _CLEANUP_H_ 1
#include <functional>
inline std::function<void()> &&
voidify(std::function<void()> &&f) {
return move(f);
}
inline const std::function<void()> &
voidify(const std::function<void()> &f) {
return f;
}
template<typename F> inline std::function<void()>
voidify(F &&f)
{
return [f]() { f(); };
}
/** \brief Container for a cleanup action.
*/
class cleanup {
std::function<void()> action_;
static void nop() {}
public:
cleanup() : action_ (nop) {}
cleanup(const cleanup &) = delete;
cleanup(cleanup &&c) : action_(c.action_) { c.release(); }
template<typename F> cleanup(F &&f) : action_ (std::forward<F>(f)) {}
template<typename... Args> cleanup(Args... args)
: action_(voidify(std::bind(args...))) {}
~cleanup() { action_(); }
cleanup &operator=(cleanup &&c) { action_.swap(c.action_); return *this; }
void reset() {
std::function<void()> old (action_);
release();
old();
}
template<typename F> void reset(F &&f) {
std::function<void()> old (action_);
action_ = std::forward<F>(f);
old();
}
template<typename... Args> void reset(Args... args) {
std::function<void()> old (action_);
action_ = std::bind(args...);
old();
}
void release() { action_ = nop; }
};
/** \brief Like a \ref std::unique_ptr, but half the size because the
* cleanup function is specified as part of the type.
*/
template<typename T, void(destructor)(T*)>
class unique_obj {
T *obj_;
public:
unique_obj() noexcept : obj_(nullptr) {}
explicit unique_obj(T *obj) noexcept : obj_(obj) {}
unique_obj(unique_obj &&uo) noexcept : obj_(uo.obj_) { uo.obj_ = nullptr; }
~unique_obj() { if (obj_) destructor(obj_); }
void reset(T *obj) { T *old = obj_; obj_ = obj; destructor(old); }
T *release() noexcept { T *old = obj_; obj_ = nullptr; return old; }
T *get() const noexcept { return obj_; }
T *&get() noexcept { return obj_; }
operator T*() const noexcept { return obj_; }
};
#endif /* !_CLEANUP_H_ */
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