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/* /////////////////////////////////////////////////////////////////////////
* File: stlsoft/util/pod_veneer.hpp
*
* Purpose: Contains the pod_veneer template class.
*
* Created: 19th January 2002
* Updated: 10th August 2009
*
* Home: http://stlsoft.org/
*
* Copyright (c) 2002-2009, 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/util/pod_veneer.hpp
*
* \brief [C++ only] Definition of the stlsoft::pod_veneer class template
* (\ref group__library__utility "Utility" Library).
*/
#ifndef STLSOFT_INCL_STLSOFT_UTIL_HPP_POD_VENEER
#define STLSOFT_INCL_STLSOFT_UTIL_HPP_POD_VENEER
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define STLSOFT_VER_STLSOFT_UTIL_HPP_POD_VENEER_MAJOR 4
# define STLSOFT_VER_STLSOFT_UTIL_HPP_POD_VENEER_MINOR 0
# define STLSOFT_VER_STLSOFT_UTIL_HPP_POD_VENEER_REVISION 1
# define STLSOFT_VER_STLSOFT_UTIL_HPP_POD_VENEER_EDIT 49
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/* /////////////////////////////////////////////////////////////////////////
* Includes
*/
#ifndef STLSOFT_INCL_STLSOFT_H_STLSOFT
# include <stlsoft/stlsoft.h>
#endif /* !STLSOFT_INCL_STLSOFT_H_STLSOFT */
#ifndef STLSOFT_INCL_STLSOFT_UTIL_HPP_CONSTRAINTS
# include <stlsoft/util/constraints.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_UTIL_HPP_CONSTRAINTS */
/* /////////////////////////////////////////////////////////////////////////
* Namespace
*/
#ifndef _STLSOFT_NO_NAMESPACE
namespace stlsoft
{
#endif /* _STLSOFT_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* Classes
*/
// class pod_veneer
/** \brief Bolts construction and/or destruction to Plain Old Data types
*
* The parameterisation of this <a href = "http://synesis.com.au/resources/articles/cpp/veneers.pdf">veneer</a>
* can be used to apply RRID or RAII semantics to a plain old data type. For
* example,
*
\code
struct Simple
{
public:
char *buffer;
};
void Init_Simple(Simple *simple);
void Uninit_Simple(Simple *simple);
struct Simple_Init { void operator ()(Simple *simple) { Init_Simple(simple); } };
struct Simple_Uninit { void operator ()(Simple *simple) { Uninit_Simple(simple); } };
void fn()
{
typedef pod_veneer<Simple, Simple_Init, Simple_Uninit> Simple_raii_t;
Simple_raii_t simple; // Init_Simple() called here
. . .
} // Uninit_Simple() called here
\endcode
*
* \param T The POD type
* \param CF The function class applied during construction
* \param DF The function class applied during destruction
*
* \ingroup concepts_veneer
*/
template< ss_typename_param_k T
, ss_typename_param_k CF
, ss_typename_param_k DF
>
class pod_veneer
: public T
{
public:
/// The value type
typedef T value_type;
/// The Plain Old Data type
typedef T pod_type;
/// The constructor function class
typedef CF constructor_function_type;
/// The destructor function class
typedef DF destructor_function_type;
/// The type of the current parameterisation
typedef pod_veneer<T, CF, DF> class_type;
public:
/// The constructor, within which CF is applied to \c this
pod_veneer()
{
// It is entirely appropriate to constrain instantiations of this class
// to default construction only, since the whole raison d'etre of this
// template is to bring RAII semantics to POD types.
// Construct the pod
constructor_function_type()(static_cast<pod_type *>(this));
}
/// The destructor, within which DF is applied to \c this
~pod_veneer() stlsoft_throw_0()
{
// There are four important points to note about the destructor
//
// 1. It does not throw an exception. Therefore, the destroying type
// must not throw an exception in its function call operator
// 2. It uses the must_be_pod constraint to ensure that the pod_type is
// a POD type
// 3. It uses the must_be_same_size constraint to ensure that the
// generated class is the same size as the pod_type, so that arrays of
// the generated class can be used where arrays of the pod_type could be
// used. The runtime assert is included for those compilers that do not
// implement compile-time asserts.
// 4. It is non-virtual, since it should not introduce a vtable (which
// would change the size of the generated class)
// 2. Must be POD
stlsoft_constraint_must_be_pod(pod_type);
// 3. Must use EDO
stlsoft_constraint_must_be_same_size(class_type, pod_type);
#if defined(STLSOFT_COMPILER_IS_WATCOM)
STLSOFT_ASSERT(sizeof(class_type) == sizeof(pod_type));
#else /* ? compiler */
STLSOFT_MESSAGE_ASSERT("pod_veneer used for inappropriate type", sizeof(class_type) == sizeof(pod_type));
#endif /* compiler */
// Destroy the pod
destructor_function_type()(static_cast<pod_type *>(this));
}
};
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _STLSOFT_NO_NAMESPACE
} // namespace stlsoft
#endif /* _STLSOFT_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !STLSOFT_INCL_STLSOFT_UTIL_HPP_POD_VENEER */
/* ///////////////////////////// end of file //////////////////////////// */