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/* /////////////////////////////////////////////////////////////////////////
* File: stlsoft/conversion/explicit_cast.hpp (originally MTExCast.h, ::SynesisStl)
*
* Purpose: Class to provide explicit cast operators.
*
* Created: 20th September 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/conversion/explicit_cast.hpp
*
* \brief [C++ only] Definition of the stlsoft::explicit_cast cast class
* (\ref group__library__conversion "Conversion" Library).
*/
#ifndef STLSOFT_INCL_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST
#define STLSOFT_INCL_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define STLSOFT_VER_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST_MAJOR 4
# define STLSOFT_VER_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST_MINOR 0
# define STLSOFT_VER_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST_REVISION 1
# define STLSOFT_VER_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST_EDIT 36
#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 */
/* /////////////////////////////////////////////////////////////////////////
* Classes
*/
// class explicit_cast
/** \brief This class is used to provide explicit casting operators.
*
* \ingroup group__library__conversion
*
* \param T The underlying type of the cast
*/
template <ss_typename_param_k T>
class explicit_cast
{
public:
typedef T value_type;
typedef explicit_cast<T> class_type;
// Construction
public:
explicit_cast(T t)
: m_t(t)
{}
#ifndef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
// For compilers that do not support partial specialisation we need to
// enforce the constraint that only basic types may be used.
~explicit_cast() stlsoft_throw_0()
{
union must_be_basic_type
{
int i;
T t;
};
}
#endif /* !STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT */
// Conversions
public:
operator value_type () const
{
return m_t;
}
// Members
private:
T m_t;
};
#ifdef STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
/** \brief Being able to cast to non-const references does not work, since
* the compilers will refuse to apply such to a temporary.
*
* \ingroup group__library__conversion
*
* Furthermore, it is too evil to contemplate (see Effective C++ #30)
* so we simply hide the constructor and conversion operator.
*/
template <ss_typename_param_k T>
class explicit_cast<T &>
{
public:
typedef T value_type;
typedef explicit_cast<T> class_type;
// Construction
private:
explicit_cast(T &);
// Conversions
private:
operator T & ();
# if defined(STLSOFT_COMPILER_IS_GCC)
public: static void f() {}
# endif /* compiler */
};
# ifdef _STLSOFT_EXPLICIT_CAST_FORCE_ALLOW_REFERENCE_TO_CONST_UDT
/* Compiler check */
# if defined(STLSOFT_COMPILER_IS_BORLAND) || \
defined(STLSOFT_COMPILER_IS_DMC) || \
defined(STLSOFT_COMPILER_IS_GCC) || \
( defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER == 1310) || \
defined(STLSOFT_COMPILER_IS_WATCOM)
// These compilers are ok
# elif defined(STLSOFT_COMPILER_IS_INTEL) || \
( defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER != 1310)
// These are not
# error The current compiler does not properly implement it
# else /* ? compiler */
// These are unknown
# error The current compiler has not been assessed as to whether it correctly translates explicit_cast for references to non-const
# endif /* compiler */
template <ss_typename_param_k T>
class explicit_cast<T const&>
{
public:
typedef T value_type;
typedef explicit_cast<T> class_type;
// Construction
public:
explicit_cast(T const& t)
: m_t(t)
{}
// Conversions
public:
operator T const& () const
{
return m_t;
}
// Members
private:
T const& m_t;
};
# else /* ? _STLSOFT_EXPLICIT_CAST_FORCE_ALLOW_REFERENCE_TO_CONST_UDT */
# ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# if defined(STLSOFT_COMPILER_IS_MSVC)
# if _MSC_VER >= 1200
# pragma warning(push)
# endif /* _MSC_VER >= 1200 */
# pragma warning(disable : 4512)
# endif /* compiler */
# ifndef STLSOFT_INCL_STLSOFT_INTERNAL_HPP_EXPLICIT_CAST_SPECIALISATIONS
# include <stlsoft/conversion/internal/explicit_cast_specialisations.hpp>
# endif /* !STLSOFT_INCL_STLSOFT_INTERNAL_HPP_EXPLICIT_CAST_SPECIALISATIONS */
# if defined(STLSOFT_COMPILER_IS_MSVC)
# if _MSC_VER >= 1200
# pragma warning(pop)
# else /* _MSC_VER */
# pragma warning(disable : 4512)
# endif /* _MSC_VER >= 1200 */
# endif /* compiler */
# endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
# endif /* _STLSOFT_EXPLICIT_CAST_FORCE_ALLOW_REFERENCE_TO_CONST_UDT */
/** \brief Not sure I really like this one, and reserve the right to remove it
* but for now it stays.
*
* \ingroup group__library__conversion
*/
template <ss_typename_param_k T>
class explicit_cast<T *>
{
public:
typedef T value_type;
typedef explicit_cast<T> class_type;
// Construction
public:
explicit_cast(T *t)
: m_t(t)
{}
// Conversions
public:
operator T * ()
{
return m_t;
}
// Members
private:
T *m_t;
};
# ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
template <ss_typename_param_k T>
class explicit_cast<T const*>
{
public:
typedef T value_type;
typedef explicit_cast<T> class_type;
// Construction
public:
explicit_cast(T const* t)
: m_t(t)
{}
// Conversions
public:
operator T const* () const
{
return m_t;
}
// Members
private:
T const* m_t;
};
# endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
#endif // STLSOFT_CF_TEMPLATE_PARTIAL_SPECIALISATION_SUPPORT
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _STLSOFT_NO_NAMESPACE
} // namespace stlsoft
#endif /* _STLSOFT_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !STLSOFT_INCL_STLSOFT_CONVERSION_HPP_EXPLICIT_CAST */
/* ///////////////////////////// end of file //////////////////////////// */