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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 //////////////////////////// */
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