#ifndef _DEUNIQUEPTR_HPP
#define _DEUNIQUEPTR_HPP
/*-------------------------------------------------------------------------
* drawElements C++ Base Library
* -----------------------------
*
* Copyright 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*//*!
* \file
* \brief Unique pointer.
*//*--------------------------------------------------------------------*/
#include "deDefs.hpp"
namespace de
{
//! Unique pointer self-test.
void UniquePtr_selfTest (void);
// Hide implementation-private types in a details namespace.
namespace details
{
//! Auxiliary struct used to pass references between unique pointers. To
//! ensure that managed pointers are deleted exactly once, this type should
//! not appear in user code.
template<typename T, class D>
struct PtrData
{
PtrData (T* p, D d) : ptr(p), deleter(d) {}
template <typename T2, class D2>
PtrData (const PtrData<T2, D2>& d) : ptr(d.ptr), deleter(d.deleter) {}
T* ptr;
D deleter;
};
template<typename T, class D>
class UniqueBase
{
public:
typedef T element_type;
typedef D deleter_type;
T* get (void) const throw() { return m_data.ptr; } //!< Get stored pointer.
D getDeleter (void) const throw() { return m_data.deleter; }
T* operator-> (void) const throw() { return get(); } //!< Get stored pointer.
T& operator* (void) const throw() { return *get(); } //!< De-reference stored pointer.
operator bool (void) const throw() { return !!get(); }
protected:
UniqueBase (T* ptr, D deleter) : m_data(ptr, deleter) {}
UniqueBase (PtrData<T, D> data) : m_data(data) {}
~UniqueBase (void);
void reset (void); //!< Delete previous pointer, set to null.
PtrData<T, D> releaseData (void) throw(); //!< Relinquish ownership, return pointer data.
void assignData (PtrData<T, D> data); //!< Set new pointer, delete previous pointer.
private:
PtrData<T, D> m_data;
};
template <typename T, class D>
UniqueBase<T, D>::~UniqueBase (void)
{
reset();
}
template <typename T, class D>
void UniqueBase<T, D>::reset (void)
{
if (m_data.ptr != DE_NULL)
{
m_data.deleter(m_data.ptr);
m_data.ptr = DE_NULL;
}
}
template <typename T, class D>
PtrData<T, D> UniqueBase<T, D>::releaseData (void) throw()
{
PtrData<T, D> data = m_data;
m_data.ptr = DE_NULL;
return data;
}
template <typename T, class D>
void UniqueBase<T, D>::assignData (PtrData<T, D> data)
{
if (data.ptr != m_data.ptr)
{
reset();
m_data = data;
}
}
/*--------------------------------------------------------------------*//*!
* \brief Movable unique pointer
*
* A MovePtr is smart pointer that retains sole ownership of a pointer and
* destroys it when it is destroyed (for example when it goes out of scope).
*
* A MovePtr can be copied and assigned to. The pointer ownership is moved to
* the newly constructer or assigned-to MovePtr. Upon assignment to a
* MovePtr, the previously managed pointer is deleted.
*
*//*--------------------------------------------------------------------*/
template<typename T, class Deleter = DefaultDeleter<T> >
class MovePtr : public UniqueBase<T, Deleter>
{
public:
MovePtr (void) : UniqueBase<T, Deleter> (DE_NULL, Deleter()) {}
explicit MovePtr (T* ptr, Deleter deleter = Deleter()) : UniqueBase<T, Deleter> (ptr, deleter) {}
MovePtr (MovePtr<T, Deleter>& other) : UniqueBase<T, Deleter> (other.releaseData()) {}
MovePtr& operator= (MovePtr<T, Deleter>& other);
T* release (void) throw();
void clear (void) { this->reset(); }
// These implicit by-value conversions to and from a PtrData are used to
// allow copying a MovePtr by value when returning from a function. To
// ensure that the managed pointer gets deleted exactly once, the PtrData
// should only exist as a temporary conversion step between two MovePtrs.
MovePtr (PtrData<T, Deleter> data) : UniqueBase<T, Deleter> (data) {}
MovePtr& operator= (PtrData<T, Deleter> data);
template<typename U, class Del2>
operator PtrData<U, Del2> (void) { return this->releaseData(); }
};
template<typename T, class D>
MovePtr<T, D>& MovePtr<T,D>::operator= (PtrData<T, D> data)
{
this->assignData(data);
return *this;
}
template<typename T, class D>
MovePtr<T, D>& MovePtr<T,D>::operator= (MovePtr<T, D>& other)
{
return (*this = other.releaseData());
}
//! Steal the managed pointer. The caller is responsible for explicitly
//! deleting the returned pointer.
template<typename T, class D>
inline T* MovePtr<T,D>::release (void) throw()
{
return this->releaseData().ptr;
}
//! Construct a MovePtr from a pointer.
template<typename T>
inline MovePtr<T> movePtr (T* ptr) { return MovePtr<T>(ptr); }
//! Allocate and construct an object and return its address as a MovePtr.
template<typename T>
inline MovePtr<T> newMovePtr (void) { return MovePtr<T>(new T()); }
template<typename T, typename P0>
inline MovePtr<T> newMovePtr (P0 p0) { return MovePtr<T>(new T(p0)); }
template<typename T, typename P0, typename P1>
inline MovePtr<T> newMovePtr (P0 p0, P1 p1) { return MovePtr<T>(new T(p0, p1)); }
template<typename T, typename P0, typename P1, typename P2>
inline MovePtr<T> newMovePtr (P0 p0, P1 p1, P2 p2) { return MovePtr<T>(new T(p0, p1, p2)); }
/*--------------------------------------------------------------------*//*!
* \brief Unique pointer
*
* UniquePtr is smart pointer that retains sole ownership of a pointer
* and destroys it when UniquePtr is destroyed (for example when UniquePtr
* goes out of scope).
*
* UniquePtr is not copyable or assignable. Pointer ownership can be transferred
* from a UniquePtr only explicitly with the move() member function.
*
* A UniquePtr can be constructed from a MovePtr. In this case it assumes
* ownership of the pointer from the MovePtr. Because a UniquePtr cannot be
* copied, direct initialization syntax must be used, i.e.:
*
* MovePtr<Foo> createFoo (void);
* UniquePtr<Foo> fooPtr(createFoo()); // NOT fooPtr = createFoo();
*
*//*--------------------------------------------------------------------*/
template<typename T, class Deleter = DefaultDeleter<T> >
class UniquePtr : public UniqueBase<T, Deleter>
{
public:
explicit UniquePtr (T* ptr, Deleter deleter = Deleter());
UniquePtr (PtrData<T, Deleter> data);
MovePtr<T, Deleter> move (void);
private:
UniquePtr (const UniquePtr<T>& other); // Not allowed!
UniquePtr operator= (const UniquePtr<T>& other); // Not allowed!
};
/*--------------------------------------------------------------------*//*!
* \brief Construct unique pointer.
* \param ptr Pointer to be managed.
*
* Pointer ownership is transferred to the UniquePtr.
*//*--------------------------------------------------------------------*/
template<typename T, class Deleter>
inline UniquePtr<T, Deleter>::UniquePtr (T* ptr, Deleter deleter)
: UniqueBase<T, Deleter> (ptr, deleter)
{
}
template<typename T, class Deleter>
inline UniquePtr<T, Deleter>::UniquePtr (PtrData<T, Deleter> data)
: UniqueBase<T, Deleter> (data)
{
}
/*--------------------------------------------------------------------*//*!
* \brief Relinquish ownership of pointer.
*
* This method returns a MovePtr that now owns the pointer. The pointer in
* the UniquePtr is set to null.
*//*--------------------------------------------------------------------*/
template<typename T, class Deleter>
inline MovePtr<T, Deleter> UniquePtr<T, Deleter>::move (void)
{
return MovePtr<T, Deleter>(this->releaseData());
}
} // details
using details::UniquePtr;
using details::MovePtr;
using details::newMovePtr;
} // de
#endif // _DEUNIQUEPTR_HPP