libstdc++-v3/include/std/numbers

// <numbers> -*- C++ -*-

// Copyright (C) 2019-2025 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 include/numbers
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_NUMBERS
#define _GLIBCXX_NUMBERS 1

#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif

#define __glibcxx_want_math_constants
#include <bits/version.h>

#ifdef __cpp_lib_math_constants // C++ >= 20

#include <type_traits>

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpedantic" // Q extension

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

/** @defgroup math_constants Mathematical constants
 *  @ingroup numerics
 *  @{
 */

/// Namespace for mathematical constants
namespace numbers
{

  /// @cond undocumented
  template<typename _Tp>
    using _Enable_if_floating = enable_if_t<is_floating_point_v<_Tp>, _Tp>;
  /// @endcond

  /// e
  template<typename _Tp>
    inline constexpr _Tp e_v
      = _Enable_if_floating<_Tp>(2.718281828459045235360287471352662498L);

  /// log_2 e
  template<typename _Tp>
    inline constexpr _Tp log2e_v
      = _Enable_if_floating<_Tp>(1.442695040888963407359924681001892137L);

  /// log_10 e
  template<typename _Tp>
    inline constexpr _Tp log10e_v
      = _Enable_if_floating<_Tp>(0.434294481903251827651128918916605082L);

  /// pi
  template<typename _Tp>
    inline constexpr _Tp pi_v
      = _Enable_if_floating<_Tp>(3.141592653589793238462643383279502884L);

  /// 1/pi
  template<typename _Tp>
    inline constexpr _Tp inv_pi_v
      = _Enable_if_floating<_Tp>(0.318309886183790671537767526745028724L);

  /// 1/sqrt(pi)
  template<typename _Tp>
    inline constexpr _Tp inv_sqrtpi_v
      = _Enable_if_floating<_Tp>(0.564189583547756286948079451560772586L);

  /// log_e 2
  template<typename _Tp>
    inline constexpr _Tp ln2_v
      = _Enable_if_floating<_Tp>(0.693147180559945309417232121458176568L);

  /// log_e 10
  template<typename _Tp>
    inline constexpr _Tp ln10_v
      = _Enable_if_floating<_Tp>(2.302585092994045684017991454684364208L);

  /// sqrt(2)
  template<typename _Tp>
    inline constexpr _Tp sqrt2_v
      = _Enable_if_floating<_Tp>(1.414213562373095048801688724209698079L);

  /// sqrt(3)
  template<typename _Tp>
    inline constexpr _Tp sqrt3_v
      = _Enable_if_floating<_Tp>(1.732050807568877293527446341505872367L);

  /// 1/sqrt(3)
  template<typename _Tp>
    inline constexpr _Tp inv_sqrt3_v
      = _Enable_if_floating<_Tp>(0.577350269189625764509148780501957456L);

  /// The Euler-Mascheroni constant
  template<typename _Tp>
    inline constexpr _Tp egamma_v
      = _Enable_if_floating<_Tp>(0.577215664901532860606512090082402431L);

  /// The golden ratio, (1+sqrt(5))/2
  template<typename _Tp>
    inline constexpr _Tp phi_v
      = _Enable_if_floating<_Tp>(1.618033988749894848204586834365638118L);

  inline constexpr double e = e_v<double>;
  inline constexpr double log2e = log2e_v<double>;
  inline constexpr double log10e = log10e_v<double>;
  inline constexpr double pi = pi_v<double>;
  inline constexpr double inv_pi = inv_pi_v<double>;
  inline constexpr double inv_sqrtpi = inv_sqrtpi_v<double>;
  inline constexpr double ln2 = ln2_v<double>;
  inline constexpr double ln10 = ln10_v<double>;
  inline constexpr double sqrt2 = sqrt2_v<double>;
  inline constexpr double sqrt3 = sqrt3_v<double>;
  inline constexpr double inv_sqrt3 = inv_sqrt3_v<double>;
  inline constexpr double egamma = egamma_v<double>;
  inline constexpr double phi = phi_v<double>;

#define __glibcxx_numbers(TYPE, SUFFIX) \
  /* e */						\
  template<>						\
    inline constexpr TYPE e_v<TYPE>			\
      = 2.718281828459045235360287471352662498##SUFFIX;	\
							\
  /* log_2 e */						\
  template<>						\
    inline constexpr TYPE log2e_v<TYPE>			\
      = 1.442695040888963407359924681001892137##SUFFIX;	\
							\
  /* log_10 e */					\
  template<>						\
    inline constexpr TYPE log10e_v<TYPE>		\
      = 0.434294481903251827651128918916605082##SUFFIX;	\
							\
  /* pi */						\
  template<>						\
    inline constexpr TYPE pi_v<TYPE>			\
      = 3.141592653589793238462643383279502884##SUFFIX;	\
							\
  /* 1/pi */						\
  template<>						\
    inline constexpr TYPE inv_pi_v<TYPE>		\
      = 0.318309886183790671537767526745028724##SUFFIX;	\
							\
  /* 1/sqrt(pi) */					\
  template<>						\
    inline constexpr TYPE inv_sqrtpi_v<TYPE>		\
      = 0.564189583547756286948079451560772586##SUFFIX;	\
							\
  /* log_e 2 */						\
  template<>						\
    inline constexpr TYPE ln2_v<TYPE>			\
      = 0.693147180559945309417232121458176568##SUFFIX;	\
							\
  /* log_e 10 */					\
  template<>						\
    inline constexpr TYPE ln10_v<TYPE>			\
      = 2.302585092994045684017991454684364208##SUFFIX;	\
							\
  /* sqrt(2) */						\
  template<>						\
    inline constexpr TYPE sqrt2_v<TYPE>			\
      = 1.414213562373095048801688724209698079##SUFFIX;	\
							\
  /* sqrt(3) */						\
  template<>						\
    inline constexpr TYPE sqrt3_v<TYPE>			\
      = 1.732050807568877293527446341505872367##SUFFIX;	\
							\
  /* 1/sqrt(3) */					\
  template<>						\
    inline constexpr TYPE inv_sqrt3_v<TYPE>		\
      = 0.577350269189625764509148780501957456##SUFFIX;	\
							\
  /* The Euler-Mascheroni constant */			\
  template<>						\
    inline constexpr TYPE egamma_v<TYPE>		\
      = 0.577215664901532860606512090082402431##SUFFIX;	\
							\
  /* The golden ratio, (1+sqrt(5))/2 */			\
  template<>						\
    inline constexpr TYPE phi_v<TYPE>			\
      = 1.618033988749894848204586834365638118##SUFFIX

#ifdef __STDCPP_FLOAT16_T__
__glibcxx_numbers (_Float16, F16);
#endif

#ifdef __STDCPP_FLOAT32_T__
__glibcxx_numbers (_Float32, F32);
#endif

#ifdef __STDCPP_FLOAT64_T__
__glibcxx_numbers (_Float64, F64);
#endif

#ifdef __STDCPP_FLOAT128_T__
__glibcxx_numbers (_Float128, F128);
#endif

#ifdef __STDCPP_BFLOAT128_T__
__glibcxx_numbers (__gnu_cxx::__bfloat16_t, BF16);
#endif

#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
__glibcxx_numbers (__float128, Q);
#endif // USE_FLOAT128

#undef __glibcxx_numbers

} // namespace numbers
/// @}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std

#pragma GCC diagnostic pop

#endif // __cpp_lib_math_constants
#endif // _GLIBCXX_NUMBERS