Subversion Repositories altor32

// Special functions -*- C++ -*-

// Copyright (C) 2006, 2009, 2010

// Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 3, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

/** @file tr1/special_function_util.h

 *  This is an internal header file, included by other library headers.

 *  Do not attempt to use it directly. @headername{tr1/cmath}

 */

//

// ISO C++ 14882 TR1: 5.2  Special functions

//

// Written by Edward Smith-Rowland based on numerous mathematics books.

#ifndef _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H

#define _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H 1

namespace std _GLIBCXX_VISIBILITY(default)

{

namespace tr1

{

  namespace __detail

  {

  _GLIBCXX_BEGIN_NAMESPACE_VERSION

    /// A class to encapsulate type dependent floating point

    /// constants.  Not everything will be able to be expressed as

    /// type logic.

    template<typename _Tp>

    struct __floating_point_constant

    {

      static const _Tp __value;

    };

    /// A structure for numeric constants.

    template<typename _Tp>

      struct __numeric_constants

      {

        ///  Constant @f$ \pi @f$.

        static _Tp __pi() throw()

        { return static_cast<_Tp>(3.1415926535897932384626433832795029L); }

        ///  Constant @f$ \pi / 2 @f$.

        static _Tp __pi_2() throw()

        { return static_cast<_Tp>(1.5707963267948966192313216916397514L); }

        ///  Constant @f$ \pi / 3 @f$.

        static _Tp __pi_3() throw()

        { return static_cast<_Tp>(1.0471975511965977461542144610931676L); }

        ///  Constant @f$ \pi / 4 @f$.

        static _Tp __pi_4() throw()

        { return static_cast<_Tp>(0.7853981633974483096156608458198757L); }

        ///  Constant @f$ 1 / \pi @f$.

        static _Tp __1_pi() throw()

        { return static_cast<_Tp>(0.3183098861837906715377675267450287L); }

        ///  Constant @f$ 2 / \sqrt(\pi) @f$.

        static _Tp __2_sqrtpi() throw()

        { return static_cast<_Tp>(1.1283791670955125738961589031215452L); }

        ///  Constant @f$ \sqrt(2) @f$.

        static _Tp __sqrt2() throw()

        { return static_cast<_Tp>(1.4142135623730950488016887242096981L); }

        ///  Constant @f$ \sqrt(3) @f$.

        static _Tp __sqrt3() throw()

        { return static_cast<_Tp>(1.7320508075688772935274463415058723L); }

        ///  Constant @f$ \sqrt(\pi/2) @f$.

        static _Tp __sqrtpio2() throw()

        { return static_cast<_Tp>(1.2533141373155002512078826424055226L); }

        ///  Constant @f$ 1 / sqrt(2) @f$.

        static _Tp __sqrt1_2() throw()

        { return static_cast<_Tp>(0.7071067811865475244008443621048490L); }

        ///  Constant @f$ \log(\pi) @f$.

        static _Tp __lnpi() throw()

        { return static_cast<_Tp>(1.1447298858494001741434273513530587L); }

        ///  Constant Euler's constant @f$ \gamma_E @f$.

        static _Tp __gamma_e() throw()

        { return static_cast<_Tp>(0.5772156649015328606065120900824024L); }

        ///  Constant Euler-Mascheroni @f$ e @f$

        static _Tp __euler() throw()

        { return static_cast<_Tp>(2.7182818284590452353602874713526625L); }

      };

#if _GLIBCXX_USE_C99_MATH && !_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC

    /// This is a wrapper for the isnan function. Otherwise, for NaN,

    /// all comparisons result in false. If/when we build a std::isnan

    /// out of intrinsics, this will disappear completely in favor of

    /// std::isnan.

    template<typename _Tp>

    inline bool __isnan(const _Tp __x)

    {

      return std::isnan(__x);

    }

#else

    template<typename _Tp>

    inline bool __isnan(const _Tp __x)

    {

      return __builtin_isnan(__x);

    }

    template<>

    inline bool __isnan<float>(const float __x)

    {

      return __builtin_isnanf(__x);

    }

    template<>

    inline bool __isnan<long double>(const long double __x)

    {

      return __builtin_isnanl(__x);

    }

#endif

  _GLIBCXX_END_NAMESPACE_VERSION

  } // namespace __detail

}

}

#endif // _GLIBCXX_TR1_SPECIAL_FUNCTION_UTIL_H