hold_ptr.hpp
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//
// Copyright (c) 2010 Artyom Beilis (Tonkikh)
//
// Distributed under the Boost Software License, Version 1.0.
// https://www.boost.org/LICENSE_1_0.txt
#ifndef BOOST_LOCALE_HOLD_PTR_H
#define BOOST_LOCALE_HOLD_PTR_H
#include <boost/locale/config.hpp>
namespace boost { namespace locale {
/// \brief a smart pointer similar to std::unique_ptr but the
/// underlying object has the same constness as the pointer itself (unlike an ordinary pointer).
template<typename T>
class hold_ptr {
public:
/// Create new empty pointer
hold_ptr() : ptr_(nullptr) {}
/// Create a pointer that holds \a v, ownership is transferred to smart pointer
explicit hold_ptr(T* v) : ptr_(v) {}
/// Destroy smart pointer and the object it owns.
~hold_ptr() { delete ptr_; }
// Non-copyable
hold_ptr(const hold_ptr&) = delete;
hold_ptr& operator=(const hold_ptr&) = delete;
// Movable
hold_ptr(hold_ptr&& other) noexcept : ptr_(other.ptr_) { other.ptr_ = nullptr; }
hold_ptr& operator=(hold_ptr&& other) noexcept
{
swap(other);
return *this;
}
/// Get a const pointer to the object
T const* get() const { return ptr_; }
/// Get a mutable pointer to the object
T* get() { return ptr_; }
/// Explicitly convertible to bool. Returns: get() != nullptr
explicit operator bool() const { return ptr_ != nullptr; }
/// Get a const reference to the object
T const& operator*() const { return *ptr_; }
/// Get a mutable reference to the object
T& operator*() { return *ptr_; }
/// Get a const pointer to the object
T const* operator->() const { return ptr_; }
/// Get a mutable pointer to the object
T* operator->() { return ptr_; }
/// Transfer an ownership on the pointer to user
T* release()
{
T* tmp = ptr_;
ptr_ = nullptr;
return tmp;
}
/// Set new value to pointer, previous object is destroyed, ownership on new object is transferred
void reset(T* p = nullptr)
{
if(ptr_)
delete ptr_;
ptr_ = p;
}
/// Swap two pointers
void swap(hold_ptr& other)
{
T* tmp = other.ptr_;
other.ptr_ = ptr_;
ptr_ = tmp;
}
private:
T* ptr_;
};
}} // namespace boost::locale
#endif