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boost_mpl/include/boost/mpl/integral_c.hpp
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2002-09-16 19:55:13 +00:00

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//-----------------------------------------------------------------------------
// boost/mpl/intergal_c.hpp header file
// See http://www.boost.org for updates, documentation, and revision history.
//-----------------------------------------------------------------------------
//
// Copyright (c) 2000-02
// Aleksey Gurtovoy
//
// Permission to use, copy, modify, distribute and sell this software
// and its documentation for any purpose is hereby granted without fee,
// provided that the above copyright notice appears in all copies and
// that both the copyright notice and this permission notice appear in
// supporting documentation. No representations are made about the
// suitability of this software for any purpose. It is provided "as is"
// without express or implied warranty.
#ifndef BOOST_MPL_INTEGRAL_C_HPP_INCLUDED
#define BOOST_MPL_INTEGRAL_C_HPP_INCLUDED
#include "boost/config.hpp"
namespace boost {
namespace mpl {
template< typename T, T N >
struct integral_c
{
BOOST_STATIC_CONSTANT(T, value = N);
typedef integral_c type;
typedef T value_type;
// have to #ifdef here: some compilers don't like the 'N + 1' form (MSVC),
// while some other don't like 'value + 1' (Borland)
#if defined(__BORLANDC__) || defined(__IBMCPP__)
typedef integral_c<T, N + 1> next;
typedef integral_c<T, N - 1> prior;
#else
typedef integral_c<T, value + 1> next;
typedef integral_c<T, value - 1> prior;
#endif
// enables uniform function call syntax for families of overloaded
// functions that return objects of both arithmetic ('int', 'long',
// 'double', etc.) and 'integral_c<..>' types (for an example, see
// "mpl/example/power.cpp")
operator T() const { return this->value; }
};
#if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
&& (!defined(BOOST_MSVC) || BOOST_MSVC != 1301) \
&& !defined(__BORLANDC__)
// 'bool' constant doesn't have 'next'/'prior' members
template< bool C >
struct integral_c<bool, C>
{
BOOST_STATIC_CONSTANT(bool, value = C);
typedef integral_c type;
operator bool() const { return this->value; }
};
#endif
} // namespace mpl
} // namespace boost
#endif // BOOST_MPL_INTEGRAL_C_HPP_INCLUDED