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/* /////////////////////////////////////////////////////////////////////////
* File: stlsoft/smartptr/ref_ptr.hpp (originally MLRelItf.h, ::SynesisStd)
*
* Purpose: Contains the ref_ptr template class.
*
* Created: 2nd November 1994
* Updated: 14th May 2010
*
* Home: http://stlsoft.org/
*
* Copyright (c) 1994-2010, Matthew Wilson and Synesis Software
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name(s) of Matthew Wilson and Synesis Software nor the names of
* any contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ////////////////////////////////////////////////////////////////////// */
/** \file stlsoft/smartptr/ref_ptr.hpp
*
* \brief [C++ only] Definition of the stlsoft::ref_ptr smart
* pointer class template
* (\ref group__library__smart_pointers "Smart Pointers" Library).
*/
#ifndef STLSOFT_INCL_STLSOFT_SMARTPTR_HPP_REF_PTR
#define STLSOFT_INCL_STLSOFT_SMARTPTR_HPP_REF_PTR
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define STLSOFT_VER_STLSOFT_SMARTPTR_HPP_REF_PTR_MAJOR 5
# define STLSOFT_VER_STLSOFT_SMARTPTR_HPP_REF_PTR_MINOR 3
# define STLSOFT_VER_STLSOFT_SMARTPTR_HPP_REF_PTR_REVISION 2
# define STLSOFT_VER_STLSOFT_SMARTPTR_HPP_REF_PTR_EDIT 489
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/* /////////////////////////////////////////////////////////////////////////
* Includes
*/
#ifndef STLSOFT_INCL_STLSOFT_H_STLSOFT
# include <stlsoft/stlsoft.h>
#endif /* !STLSOFT_INCL_STLSOFT_H_STLSOFT */
/* /////////////////////////////////////////////////////////////////////////
* Namespace
*/
#ifndef _STLSOFT_NO_NAMESPACE
namespace stlsoft
{
#endif /* _STLSOFT_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* Helper shims
*/
/** \brief Control shim for adding a reference on a reference-counted
* interface (RCI)
*
* \ingroup group__library__smart_pointers
*
* \note The generic shim expects the RCI to have a method named AddRef(), which
* has either no parameters, or has all default parameters
*
* \note The behaviour of the ref_ptr is undefined if this method throws an
* exception
*/
template<ss_typename_param_k I>
inline void add_reference(I* pi)
{
STLSOFT_ASSERT(NULL != pi);
pi->AddRef();
}
/** \brief Control shim for releasing a reference on a reference-counted
* interface (RCI)
*
* \ingroup group__library__smart_pointers
*
* \note The generic shim expects the RCI to have a method named Release(), which
* has either no parameters, or has all default parameters
*
* \note The behaviour of the ref_ptr is undefined if this method throws an
* exception
*/
template<ss_typename_param_k I>
inline void release_reference(I* pi)
{
STLSOFT_ASSERT(NULL != pi);
pi->Release();
}
/* /////////////////////////////////////////////////////////////////////////
* Classes
*/
/** \brief This class provides RAII-safe handling of reference-counted
* interfaces (RCIs). Its notable feature is that it supports forward
* declaration of the leaf interface so long as the base counting
* interface is visible in the scope of the template parameterisation.
*
* \ingroup group__library__smart_pointers
*
* \param T The counted type (i.e. a concrete class)
* \param I The interface type
* \param U The upcast intermediate type
*/
template< ss_typename_param_k T
, ss_typename_param_k I = T
, ss_typename_param_k U = I
>
class ref_ptr
{
/// \name Types
/// @{
public:
/// \brief The Boolean type
typedef bool_t bool_type;
/// \brief The interface type: the type of the RCI (Reference-Counted Interface)
typedef I interface_type;
/// \brief The counted type: the concrete type of the objects whose instances will be managed
typedef T counted_type;
/// \brief The up-cast type: the type used to disambiguate upcasts between T and I
typedef U upcast_type;
/// \brief The current instantiation of the type
typedef ref_ptr<T, I, U> class_type;
/// \brief This to be member-type-compatible with std::auto_ptr
typedef I element_type;
/// \brief This is to be compatible with the get_invoker component
typedef counted_type* resource_type;
typedef counted_type const* const_resource_type;
/// @}
/// \name Implementation
/// @{
private:
/// \brief Helper function to effect downcast from interface type to counted type
static counted_type* c_from_i(interface_type* i)
{
return static_cast<counted_type*>(static_cast<upcast_type*>(i));
}
/// \brief Helper function to effect downcast from interface type to counted type
static counted_type const* c_from_i(interface_type const* i)
{
return static_cast<counted_type const*>(static_cast<upcast_type const*>(i));
}
/// \brief Helper function to effect upcast from counted type to interface type
static interface_type* i_from_c(counted_type* c)
{
return static_cast<upcast_type*>(c);
}
#if defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER == 1300
/// \brief Helper function to effect upcast from const counted type to interface type
static interface_type* i_from_const_c(counted_type const* cc)
{
counted_type* c = const_cast<counted_type*>(cc);
return i_from_c(c);
}
#endif /* compiler */
/// @}
/// \name Construction
/// @{
public:
/// \brief Default constructor
///
/// Constructs and empty instance
ref_ptr()
: m_pi(NULL)
{}
/// \brief Construct from a raw pointer to the counted type, and a boolean that
/// indicates whether a reference should be taken on the instance.
///
/// \param c Pointer to a counted_type. May be NULL
/// \param bAddRef parameter that determines whether reference will be
/// <i>consumed</i> (<code>false</code>) or <i>borrowed</i>
/// (<code>true</code>).
///
/// \note It is usual that ref_ptr is used to "sink" an instance, i.e. to take
/// ownership of it. In such a case, \c false should be specified as the second
/// parameter. If, however, a reference is being "borrowed", then \c true should
/// be specified.
ref_ptr(counted_type* c, bool_type bAddRef)
: m_pi(i_from_c(c))
{
if( bAddRef &&
NULL != m_pi)
{
add_reference(m_pi);
}
}
/// \brief Creates a copy of the given ref_ptr instance, and increments the
/// reference count on its referent object, if any
///
/// \param rhs The instance to copy
ref_ptr(class_type const& rhs)
: m_pi(rhs.m_pi)
{
if(NULL != m_pi)
{
add_reference(m_pi);
}
}
#if !defined(STLSOFT_COMPILER_IS_MSVC) || \
_MSC_VER > 1100
/// \brief Copy constructs from an instance with different interface and/or
/// counted type
///
/// \note The interface types of the copying and copied instance must be
/// compatible
template< ss_typename_param_k T2
, ss_typename_param_k I2
, ss_typename_param_k U2
>
# if defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER == 1300
ref_ptr(ref_ptr<T2, I2, U2> const& rhs)
# if 0
// We cannot use this form, as it would lead to instances with different
// counted_type being cross cast invisibly. This would be a *very bad thing*
: m_pi(rhs.m_pi)
# else /* ? 0 */
: m_pi(i_from_const_c(rhs.get()))
# endif /* 0 */
{
if(NULL != m_pi)
{
add_reference(m_pi);
}
}
# else /* ? compiler */
ref_ptr(ref_ptr<T2, I2, U2>& rhs)
# if 0
// We cannot use this form, as it would lead to instances with different
// counted_type being cross cast invisibly. This would be a *very bad thing*
: m_pi(rhs.m_pi)
# else /* ? 0 */
: m_pi(i_from_c(rhs.get()))
# endif /* 0 */
{
if(NULL != m_pi)
{
add_reference(m_pi);
}
}
# endif /* compiler */
#endif /* compiler */
#if !defined(STLSOFT_COMPILER_IS_INTEL) && \
!defined(STLSOFT_COMPILER_IS_MWERKS) && \
0
template< ss_typename_param_k I2
, ss_typename_param_k U2
>
explicit ref_ptr(ref_ptr<T, I2, U2>& rhs)
: m_pi(rhs.m_pi)
{
if(NULL != m_pi)
{
add_reference(m_pi);
}
}
#endif /* compiler */
/// \brief Destructor
///
/// If the ref_ptr instance is still holding a pointer to a managed instance,
/// it will be released.
~ref_ptr() stlsoft_throw_0()
{
if(NULL != m_pi)
{
release_reference(m_pi);
}
}
/// \brief Copy assignment from a ref_ptr instance of the same type
///
/// \note It is strongly exception-safe, as long as the implementations of the
/// add-ref and release functions - as utilised in the \c add_reference() and
/// \c release_reference() control shims - do not throw (which they must not).
class_type& operator =(class_type const& rhs)
{
class_type t(rhs);
t.swap(*this);
return *this;
}
#if !defined(STLSOFT_COMPILER_IS_MSVC) || \
( _MSC_VER > 1100 && \
_MSC_VER != 1300)
/// \brief Copy assignment from an instance of ref_ptr with a different counted_type (but
/// the same interface type).
///
/// \note This function template uses the copy constructor template, and has the same
/// instantiation restrictions
///
/// \note It is strongly exception-safe, as long as the implementations of the
/// add-ref and release functions - as utilised in the \c add_reference() and
/// \c release_reference() control shims - do not throw (which they must not).
template< ss_typename_param_k T2
, ss_typename_param_k U2
>
class_type& operator =(ref_ptr<T2, I, U2>& rhs)
{
class_type t(rhs);
t.swap(*this);
return *this;
}
#endif /* compiler */
#if !defined(STLSOFT_COMPILER_IS_INTEL) && \
!defined(STLSOFT_COMPILER_IS_MWERKS) && \
0
template< ss_typename_param_k I2
, ss_typename_param_k U2
>
class_type& operator =(ref_ptr<T, I2, U2>& rhs)
{
class_type t(rhs);
t.swap(*this);
return *this;
}
#endif /* compiler */
/// @}
/// \name Operations
/// @{
public:
/// \brief Swaps the managed instance of \c this with \c rhs
///
/// \note It provides the no-throw guarantee
void swap(class_type& rhs)
{
interface_type* t = rhs.m_pi;
rhs.m_pi = m_pi;
m_pi = t;
}
/// \brief Assigns a reference-counted type to the smart pointer.
///
/// \param c Pointer to a counted_type. May be NULL
/// \param bAddRef parameter that determines whether reference will be
/// <i>consumed</i> (<code>false</code>) or <i>borrowed</i>
/// (<code>true</code>).
void set(counted_type* c, bool_type bAddRef)
{
class_type t(c, bAddRef);
t.swap(*this);
}
/// Closes the instance, releasing the managed pointer.
///
/// \note Calling this method more than once has no effect.
void close()
{
if(NULL != m_pi)
{
release_reference(m_pi);
m_pi = NULL;
}
}
/// \brief Detaches the managed instance, and returns it to the caller, which
/// takes responsibility for ensuring that the resource is not leaked
counted_type* detach()
{
counted_type* r = class_type::c_from_i(m_pi);
m_pi = NULL;
return r;
}
/// @}
/// \name Equality Comparison
/// @{
public:
/// \brief Evaluates whether two instances are equal
bool_type equal(class_type const& rhs) const
{
return m_pi == rhs.m_pi;
}
/// @}
/// \name Accessors
/// @{
public:
/// \brief Determines whether the instance is empty
bool_type empty() const
{
return NULL == m_pi;
}
/// \brief Determines whether the instance is empty
bool_type operator !() const
{
return empty();
}
/// \brief Provides raw-pointer access to the instance
counted_type* get() const
{
return class_type::c_from_i(m_pi);
}
/// \brief Returns the interface pointer
///
/// \pre The instance must not be empty; otherwise behaviour is
/// undefined
counted_type* operator ->()
{
STLSOFT_MESSAGE_ASSERT("Dereferencing a NULL pointer!", NULL != m_pi);
return class_type::c_from_i(m_pi);
}
/// \brief Returns the interface pointer
///
/// \pre The instance must not be empty; otherwise behaviour is
/// undefined
counted_type const* operator ->() const
{
STLSOFT_MESSAGE_ASSERT("Dereferencing a NULL pointer!", NULL != m_pi);
return class_type::c_from_i(m_pi);
}
/// \brief Returns a reference to the managed instance
///
/// \pre The instance must not be empty; otherwise behaviour is
/// undefined
counted_type& operator *()
{
STLSOFT_MESSAGE_ASSERT("Dereferencing a NULL pointer!", NULL != m_pi);
return *class_type::c_from_i(m_pi);
}
/// \brief Returns a reference to the managed instance
///
/// \pre The instance must not be empty; otherwise behaviour is
/// undefined
counted_type const& operator *() const
{
STLSOFT_MESSAGE_ASSERT("Dereferencing a NULL pointer!", NULL != m_pi);
return *class_type::c_from_i(m_pi);
}
/// @}
/// \name Members
/// @{
private:
interface_type* m_pi;
/// @}
};
/* /////////////////////////////////////////////////////////////////////////
* Operators
*/
template< ss_typename_param_k T
, ss_typename_param_k I
, ss_typename_param_k U
>
inline ss_bool_t operator ==(ref_ptr<T, I, U> const& lhs, ref_ptr<T, I, U> const& rhs)
{
return lhs.equal(rhs);
}
template< ss_typename_param_k T
, ss_typename_param_k I
, ss_typename_param_k U
>
inline ss_bool_t operator !=(ref_ptr<T, I, U> const& lhs, ref_ptr<T, I, U> const& rhs)
{
return !lhs.equal(rhs);
}
/* /////////////////////////////////////////////////////////////////////////
* swapping
*/
template< ss_typename_param_k T
, ss_typename_param_k I
, ss_typename_param_k U
>
inline void swap(ref_ptr<T, I, U>& lhs, ref_ptr<T, I, U>& rhs)
{
lhs.swap(rhs);
}
/* /////////////////////////////////////////////////////////////////////////
* Shims
*/
/** \brief is_empty shim
*
* \ingroup group__library__smart_pointers
*/
template< ss_typename_param_k T
, ss_typename_param_k I /* = T */
, ss_typename_param_k U /* = I */
>
inline ss_bool_t is_empty(ref_ptr<T, I, U> const& p)
{
return NULL == p.get();
}
/** \brief get_ptr shim
*
* \ingroup group__library__smart_pointers
*/
template< ss_typename_param_k T
, ss_typename_param_k I /* = T */
, ss_typename_param_k U /* = I */
>
inline T* get_ptr(ref_ptr<T, I, U> const& p)
{
return p.get();
}
/** \brief Insertion operator shim
*
* \ingroup group__library__smart_pointers
*/
template< ss_typename_param_k S
, ss_typename_param_k T
, ss_typename_param_k I /* = T */
, ss_typename_param_k U /* = I */
>
inline S& operator <<(S& s, ref_ptr<T, I, U> const& p)
{
return s << *p;
}
/* /////////////////////////////////////////////////////////////////////////
* Unit-testing
*/
#ifdef STLSOFT_UNITTEST
# include "./unittest/ref_ptr_unittest_.h"
#endif /* STLSOFT_UNITTEST */
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _STLSOFT_NO_NAMESPACE
} // namespace stlsoft
#endif /* _STLSOFT_NO_NAMESPACE */
/* In the special case of Intel behaving as VC++ 7.0 or earlier on Win32, we
* illegally insert into the std namespace.
*/
#if defined(STLSOFT_CF_std_NAMESPACE)
# if ( ( defined(STLSOFT_COMPILER_IS_INTEL) && \
defined(_MSC_VER))) && \
_MSC_VER < 1310
namespace std
{
template< ss_typename_param_k T
, ss_typename_param_k I
, ss_typename_param_k U
>
inline void swap(stlsoft_ns_qual(ref_ptr)<T, I, U>& lhs, stlsoft_ns_qual(ref_ptr)<T, I, U>& rhs)
{
lhs.swap(rhs);
}
} // namespace std
# endif /* INTEL && _MSC_VER < 1310 */
#endif /* STLSOFT_CF_std_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !STLSOFT_INCL_STLSOFT_SMARTPTR_HPP_REF_PTR */
/* ///////////////////////////// end of file //////////////////////////// */