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/* /////////////////////////////////////////////////////////////////////////
* File: stlsoft/util/operator_bool.hpp
*
* Purpose: A robust and portable operator bool generator class.
*
* Created: 5th November 2003
* Updated: 10th August 2009
*
* Home: http://stlsoft.org/
*
* Copyright (c) 2003-2009, 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/operator_bool.hpp
*
* \brief [C++ only] Definition of the stlsoft::operator_bool_generator
* class template
* (\ref group__library__utility "Utility" Library).
*/
#ifndef STLSOFT_INCL_STLSOFT_UTIL_HPP_OPERATOR_BOOL
#define STLSOFT_INCL_STLSOFT_UTIL_HPP_OPERATOR_BOOL
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define STLSOFT_VER_STLSOFT_UTIL_HPP_OPERATOR_BOOL_MAJOR 4
# define STLSOFT_VER_STLSOFT_UTIL_HPP_OPERATOR_BOOL_MINOR 0
# define STLSOFT_VER_STLSOFT_UTIL_HPP_OPERATOR_BOOL_REVISION 1
# define STLSOFT_VER_STLSOFT_UTIL_HPP_OPERATOR_BOOL_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 */
/* /////////////////////////////////////////////////////////////////////////
* Macros
*/
/** \brief \def STLSOFT_DEFINE_OPERATOR_BOOL_TYPES(U, G, B)
* Defines the types for a type-safe boolean operator
*
* \ingroup group__library__utility
*
* \param U The Unique type. This is usually the \c class_type member type of the
* class for which we are providing the boolean operator, but it could be any type.
* \param G The Generator type. This is the type you use to qualify your call
* to translate() inside the boolean operator
* \param B The Boolean type. This is the type of the boolean operator
*/
# define STLSOFT_DEFINE_OPERATOR_BOOL_TYPES(U, G, B) \
\
typedef stlsoft_ns_qual(operator_bool_generator)<U>::class_type G; \
typedef G::return_type B
/** \brief \def STLSOFT_DEFINE_OPERATOR_BOOL_TYPES(U, G, B)
* Defines the types for a type-safe boolean operator, for use in templates
*
* \ingroup group__library__utility
*
* \param U The Unique type. This is usually the \c class_type member type of the
* class for which we are providing the boolean operator, but it could be any type.
* \param G The Generator type. This is the type you use to qualify your call
* to translate() inside the boolean operator
* \param B The Boolean type. This is the type of the boolean operator
*
* \note This is identical in form and purpose to STLSOFT_DEFINE_OPERATOR_BOOL_TYPES(),
* except that it must be used for implementing operator boolean for templates
*/
#if defined(STLSOFT_COMPILER_IS_BORLAND) || \
( defined(STLSOFT_COMPILER_IS_MSVC) && \
_MSC_VER < 1300)
# define STLSOFT_DEFINE_OPERATOR_BOOL_TYPES_T(U, G, B) \
\
STLSOFT_DEFINE_OPERATOR_BOOL_TYPES(U, G, B)
#else /* ? compiler */
# define STLSOFT_DEFINE_OPERATOR_BOOL_TYPES_T(U, G, B) \
\
typedef ss_typename_param_k stlsoft_ns_qual(operator_bool_generator)<U>::class_type G; \
typedef ss_typename_param_k G::return_type B
#endif /* compiler */
/* /////////////////////////////////////////////////////////////////////////
* Classes
*/
/** \brief Template which provides the types and conversion operations for safe and
* highly-portable "<code>operator bool() const</code>".
*
* \ingroup group__library__utility
*/
template <ss_typename_param_k T>
struct operator_bool_generator
{
public:
typedef operator_bool_generator<T> class_type;
#ifdef STLSOFT_CF_OPERATOR_BOOL_AS_OPERATOR_POINTER_TO_MEMBER_SUPPORT
typedef int class_type::*return_type;
/// Returns the value representing the true condition
static return_type true_value()
{
return &class_type::i;
}
private:
int i;
public:
#else
typedef class_type const* return_type;
/// Returns the value representing the true condition
static return_type true_value()
{
class_type t;
void *p = static_cast<void*>(&t);
return static_cast<return_type>(p);
}
#endif // STLSOFT_CF_OPERATOR_BOOL_AS_OPERATOR_POINTER_TO_MEMBER_SUPPORT
/// Returns the value representing the false condition
static return_type false_value()
{
return static_cast<return_type>(0);
}
/// Does the ternary operator for you
#ifdef STLSOFT_CF_MEMBER_TEMPLATE_FUNCTION_SUPPORT
template <ss_typename_param_k U>
static return_type translate(U b)
#else /* ? STLSOFT_CF_MEMBER_TEMPLATE_FUNCTION_SUPPORT */
static return_type translate(ss_bool_t b)
#endif // STLSOFT_CF_MEMBER_TEMPLATE_FUNCTION_SUPPORT
{
return b ? true_value() : false_value();
}
private:
void operator delete(void*);
};
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _STLSOFT_NO_NAMESPACE
} // namespace stlsoft
#endif /* _STLSOFT_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !STLSOFT_INCL_STLSOFT_UTIL_HPP_OPERATOR_BOOL */
/* ///////////////////////////// end of file //////////////////////////// */