<h2>Editing File: /usr/include/c++/8/cmath</h2><form method='post'><textarea name='content' class='file-edit'>// -*- C++ -*- C forwarding header.

// Copyright (C) 1997-2018 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
// &lt;http://www.gnu.org/licenses/&gt;.

/** @file include/cmath
 *  This is a Standard C++ Library file.  You should @c \#include this file
 *  in your programs, rather than any of the @a *.h implementation files.
 *
 *  This is the C++ version of the Standard C Library header @c math.h,
 *  and its contents are (mostly) the same as that header, but are all
 *  contained in the namespace @c std (except for names which are defined
 *  as macros in C).
 */

//
// ISO C++ 14882: 26.5  C library
//

#pragma GCC system_header

#include &lt;bits/c++config.h&gt;
#include &lt;bits/cpp_type_traits.h&gt;
#include &lt;ext/type_traits.h&gt;
#define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
#include_next &lt;math.h&gt;
#undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS
#include &lt;bits/std_abs.h&gt;

#ifndef _GLIBCXX_CMATH
#define _GLIBCXX_CMATH 1

// Get rid of those macros defined in &lt;math.h&gt; in lieu of real functions.
#undef div
#undef acos
#undef asin
#undef atan
#undef atan2
#undef ceil
#undef cos
#undef cosh
#undef exp
#undef fabs
#undef floor
#undef fmod
#undef frexp
#undef ldexp
#undef log
#undef log10
#undef modf
#undef pow
#undef sin
#undef sinh
#undef sqrt
#undef tan
#undef tanh

extern &quot;C++&quot;
{
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  using ::acos;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  acos(float __x)
  { return __builtin_acosf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  acos(long double __x)
  { return __builtin_acosl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    acos(_Tp __x)
    { return __builtin_acos(__x); }

  using ::asin;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  asin(float __x)
  { return __builtin_asinf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  asin(long double __x)
  { return __builtin_asinl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    asin(_Tp __x)
    { return __builtin_asin(__x); }

  using ::atan;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  atan(float __x)
  { return __builtin_atanf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  atan(long double __x)
  { return __builtin_atanl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    atan(_Tp __x)
    { return __builtin_atan(__x); }

  using ::atan2;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  atan2(float __y, float __x)
  { return __builtin_atan2f(__y, __x); }

  inline _GLIBCXX_CONSTEXPR long double
  atan2(long double __y, long double __x)
  { return __builtin_atan2l(__y, __x); }
#endif

  template&lt;typename _Tp, typename _Up&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    atan2(_Tp __y, _Up __x)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return atan2(__type(__y), __type(__x));
    }

  using ::ceil;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  ceil(float __x)
  { return __builtin_ceilf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  ceil(long double __x)
  { return __builtin_ceill(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    ceil(_Tp __x)
    { return __builtin_ceil(__x); }

  using ::cos;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  cos(float __x)
  { return __builtin_cosf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  cos(long double __x)
  { return __builtin_cosl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    cos(_Tp __x)
    { return __builtin_cos(__x); }

  using ::cosh;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  cosh(float __x)
  { return __builtin_coshf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  cosh(long double __x)
  { return __builtin_coshl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    cosh(_Tp __x)
    { return __builtin_cosh(__x); }

  using ::exp;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  exp(float __x)
  { return __builtin_expf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  exp(long double __x)
  { return __builtin_expl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    exp(_Tp __x)
    { return __builtin_exp(__x); }

  using ::fabs;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  fabs(float __x)
  { return __builtin_fabsf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  fabs(long double __x)
  { return __builtin_fabsl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    fabs(_Tp __x)
    { return __builtin_fabs(__x); }

  using ::floor;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  floor(float __x)
  { return __builtin_floorf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  floor(long double __x)
  { return __builtin_floorl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    floor(_Tp __x)
    { return __builtin_floor(__x); }

  using ::fmod;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  fmod(float __x, float __y)
  { return __builtin_fmodf(__x, __y); }

  inline _GLIBCXX_CONSTEXPR long double
  fmod(long double __x, long double __y)
  { return __builtin_fmodl(__x, __y); }
#endif

  template&lt;typename _Tp, typename _Up&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    fmod(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return fmod(__type(__x), __type(__y));
    }

  using ::frexp;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline float
  frexp(float __x, int* __exp)
  { return __builtin_frexpf(__x, __exp); }

  inline long double
  frexp(long double __x, int* __exp)
  { return __builtin_frexpl(__x, __exp); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    frexp(_Tp __x, int* __exp)
    { return __builtin_frexp(__x, __exp); }

  using ::ldexp;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  ldexp(float __x, int __exp)
  { return __builtin_ldexpf(__x, __exp); }

  inline _GLIBCXX_CONSTEXPR long double
  ldexp(long double __x, int __exp)
  { return __builtin_ldexpl(__x, __exp); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    ldexp(_Tp __x, int __exp)
    { return __builtin_ldexp(__x, __exp); }

  using ::log;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  log(float __x)
  { return __builtin_logf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  log(long double __x)
  { return __builtin_logl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    log(_Tp __x)
    { return __builtin_log(__x); }

  using ::log10;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  log10(float __x)
  { return __builtin_log10f(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  log10(long double __x)
  { return __builtin_log10l(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                    double&gt;::__type
    log10(_Tp __x)
    { return __builtin_log10(__x); }

  using ::modf;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline float
  modf(float __x, float* __iptr)
  { return __builtin_modff(__x, __iptr); }

  inline long double
  modf(long double __x, long double* __iptr)
  { return __builtin_modfl(__x, __iptr); }
#endif

  using ::pow;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  pow(float __x, float __y)
  { return __builtin_powf(__x, __y); }

  inline _GLIBCXX_CONSTEXPR long double
  pow(long double __x, long double __y)
  { return __builtin_powl(__x, __y); }

#if __cplusplus &lt; 201103L
  // _GLIBCXX_RESOLVE_LIB_DEFECTS
  // DR 550. What should the return type of pow(float,int) be?
  inline double
  pow(double __x, int __i)
  { return __builtin_powi(__x, __i); }

  inline float
  pow(float __x, int __n)
  { return __builtin_powif(__x, __n); }

  inline long double
  pow(long double __x, int __n)
  { return __builtin_powil(__x, __n); }
#endif
#endif

  template&lt;typename _Tp, typename _Up&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    pow(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return pow(__type(__x), __type(__y));
    }

  using ::sin;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  sin(float __x)
  { return __builtin_sinf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  sin(long double __x)
  { return __builtin_sinl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    sin(_Tp __x)
    { return __builtin_sin(__x); }

  using ::sinh;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  sinh(float __x)
  { return __builtin_sinhf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  sinh(long double __x)
  { return __builtin_sinhl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    sinh(_Tp __x)
    { return __builtin_sinh(__x); }

  using ::sqrt;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  sqrt(float __x)
  { return __builtin_sqrtf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  sqrt(long double __x)
  { return __builtin_sqrtl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    sqrt(_Tp __x)
    { return __builtin_sqrt(__x); }

  using ::tan;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  tan(float __x)
  { return __builtin_tanf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  tan(long double __x)
  { return __builtin_tanl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    tan(_Tp __x)
    { return __builtin_tan(__x); }

  using ::tanh;

#ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  inline _GLIBCXX_CONSTEXPR float
  tanh(float __x)
  { return __builtin_tanhf(__x); }

  inline _GLIBCXX_CONSTEXPR long double
  tanh(long double __x)
  { return __builtin_tanhl(__x); }
#endif

  template&lt;typename _Tp&gt;
    inline _GLIBCXX_CONSTEXPR
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    double&gt;::__type
    tanh(_Tp __x)
    { return __builtin_tanh(__x); }

#if _GLIBCXX_USE_C99_MATH
#if !_GLIBCXX_USE_C99_FP_MACROS_DYNAMIC

// These are possible macros imported from C99-land.
#undef fpclassify
#undef isfinite
#undef isinf
#undef isnan
#undef isnormal
#undef signbit
#undef isgreater
#undef isgreaterequal
#undef isless
#undef islessequal
#undef islessgreater
#undef isunordered

#if __cplusplus &gt;= 201103L

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr int
  fpclassify(float __x)
  { return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL,
				FP_SUBNORMAL, FP_ZERO, __x); }

  constexpr int
  fpclassify(double __x)
  { return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL,
				FP_SUBNORMAL, FP_ZERO, __x); }

  constexpr int
  fpclassify(long double __x)
  { return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL,
				FP_SUBNORMAL, FP_ZERO, __x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              int&gt;::__type
    fpclassify(_Tp __x)
    { return __x != 0 ? FP_NORMAL : FP_ZERO; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isfinite(float __x)
  { return __builtin_isfinite(__x); }

  constexpr bool
  isfinite(double __x)
  { return __builtin_isfinite(__x); }

  constexpr bool
  isfinite(long double __x)
  { return __builtin_isfinite(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              bool&gt;::__type
    isfinite(_Tp __x)
    { return true; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isinf(float __x)
  { return __builtin_isinf(__x); }

#if _GLIBCXX_HAVE_OBSOLETE_ISINF \
  &amp;&amp; !_GLIBCXX_NO_OBSOLETE_ISINF_ISNAN_DYNAMIC
  using ::isinf;
#else
  constexpr bool
  isinf(double __x)
  { return __builtin_isinf(__x); }
#endif

  constexpr bool
  isinf(long double __x)
  { return __builtin_isinf(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              bool&gt;::__type
    isinf(_Tp __x)
    { return false; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isnan(float __x)
  { return __builtin_isnan(__x); }

#if _GLIBCXX_HAVE_OBSOLETE_ISNAN \
  &amp;&amp; !_GLIBCXX_NO_OBSOLETE_ISINF_ISNAN_DYNAMIC
  using ::isnan;
#else
  constexpr bool
  isnan(double __x)
  { return __builtin_isnan(__x); }
#endif

  constexpr bool
  isnan(long double __x)
  { return __builtin_isnan(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              bool&gt;::__type
    isnan(_Tp __x)
    { return false; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isnormal(float __x)
  { return __builtin_isnormal(__x); }

  constexpr bool
  isnormal(double __x)
  { return __builtin_isnormal(__x); }

  constexpr bool
  isnormal(long double __x)
  { return __builtin_isnormal(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              bool&gt;::__type
    isnormal(_Tp __x)
    { return __x != 0 ? true : false; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  // Note: middle-end/36757 is fixed, __builtin_signbit is type-generic.
  constexpr bool
  signbit(float __x)
  { return __builtin_signbit(__x); }

  constexpr bool
  signbit(double __x)
  { return __builtin_signbit(__x); }

  constexpr bool
  signbit(long double __x)
  { return __builtin_signbit(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value,
                                              bool&gt;::__type
    signbit(_Tp __x)
    { return __x &lt; 0 ? true : false; }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isgreater(float __x, float __y)
  { return __builtin_isgreater(__x, __y); }

  constexpr bool
  isgreater(double __x, double __y)
  { return __builtin_isgreater(__x, __y); }

  constexpr bool
  isgreater(long double __x, long double __y)
  { return __builtin_isgreater(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    isgreater(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_isgreater(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isgreaterequal(float __x, float __y)
  { return __builtin_isgreaterequal(__x, __y); }

  constexpr bool
  isgreaterequal(double __x, double __y)
  { return __builtin_isgreaterequal(__x, __y); }

  constexpr bool
  isgreaterequal(long double __x, long double __y)
  { return __builtin_isgreaterequal(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    isgreaterequal(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_isgreaterequal(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isless(float __x, float __y)
  { return __builtin_isless(__x, __y); }

  constexpr bool
  isless(double __x, double __y)
  { return __builtin_isless(__x, __y); }

  constexpr bool
  isless(long double __x, long double __y)
  { return __builtin_isless(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    isless(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_isless(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  islessequal(float __x, float __y)
  { return __builtin_islessequal(__x, __y); }

  constexpr bool
  islessequal(double __x, double __y)
  { return __builtin_islessequal(__x, __y); }

  constexpr bool
  islessequal(long double __x, long double __y)
  { return __builtin_islessequal(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    islessequal(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_islessequal(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  islessgreater(float __x, float __y)
  { return __builtin_islessgreater(__x, __y); }

  constexpr bool
  islessgreater(double __x, double __y)
  { return __builtin_islessgreater(__x, __y); }

  constexpr bool
  islessgreater(long double __x, long double __y)
  { return __builtin_islessgreater(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    islessgreater(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_islessgreater(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr bool
  isunordered(float __x, float __y)
  { return __builtin_isunordered(__x, __y); }

  constexpr bool
  isunordered(double __x, double __y)
  { return __builtin_isunordered(__x, __y); }

  constexpr bool
  isunordered(long double __x, long double __y)
  { return __builtin_isunordered(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename
    __gnu_cxx::__enable_if&lt;(__is_arithmetic&lt;_Tp&gt;::__value
			    &amp;&amp; __is_arithmetic&lt;_Up&gt;::__value), bool&gt;::__type
    isunordered(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return __builtin_isunordered(__type(__x), __type(__y));
    }
#endif

#else

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    fpclassify(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL,
				  FP_SUBNORMAL, FP_ZERO, __type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isfinite(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isfinite(__type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isinf(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isinf(__type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isnan(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isnan(__type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isnormal(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isnormal(__type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    signbit(_Tp __f)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_signbit(__type(__f));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isgreater(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isgreater(__type(__f1), __type(__f2));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isgreaterequal(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isgreaterequal(__type(__f1), __type(__f2));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isless(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isless(__type(__f1), __type(__f2));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    islessequal(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_islessequal(__type(__f1), __type(__f2));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    islessgreater(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_islessgreater(__type(__f1), __type(__f2));
    }

  template&lt;typename _Tp&gt;
    inline typename __gnu_cxx::__enable_if&lt;__is_arithmetic&lt;_Tp&gt;::__value,
					   int&gt;::__type
    isunordered(_Tp __f1, _Tp __f2)
    {
      typedef typename __gnu_cxx::__promote&lt;_Tp&gt;::__type __type;
      return __builtin_isunordered(__type(__f1), __type(__f2));
    }

#endif // C++11
#endif /* _GLIBCXX_USE_C99_FP_MACROS_DYNAMIC */
#endif /* _GLIBCXX_USE_C99_MATH */

#if __cplusplus &gt;= 201103L

#ifdef _GLIBCXX_USE_C99_MATH_TR1

#undef acosh
#undef acoshf
#undef acoshl
#undef asinh
#undef asinhf
#undef asinhl
#undef atanh
#undef atanhf
#undef atanhl
#undef cbrt
#undef cbrtf
#undef cbrtl
#undef copysign
#undef copysignf
#undef copysignl
#undef erf
#undef erff
#undef erfl
#undef erfc
#undef erfcf
#undef erfcl
#undef exp2
#undef exp2f
#undef exp2l
#undef expm1
#undef expm1f
#undef expm1l
#undef fdim
#undef fdimf
#undef fdiml
#undef fma
#undef fmaf
#undef fmal
#undef fmax
#undef fmaxf
#undef fmaxl
#undef fmin
#undef fminf
#undef fminl
#undef hypot
#undef hypotf
#undef hypotl
#undef ilogb
#undef ilogbf
#undef ilogbl
#undef lgamma
#undef lgammaf
#undef lgammal
#ifndef _GLIBCXX_NO_C99_ROUNDING_FUNCS
#undef llrint
#undef llrintf
#undef llrintl
#undef llround
#undef llroundf
#undef llroundl
#endif
#undef log1p
#undef log1pf
#undef log1pl
#undef log2
#undef log2f
#undef log2l
#undef logb
#undef logbf
#undef logbl
#undef lrint
#undef lrintf
#undef lrintl
#undef lround
#undef lroundf
#undef lroundl
#undef nan
#undef nanf
#undef nanl
#undef nearbyint
#undef nearbyintf
#undef nearbyintl
#undef nextafter
#undef nextafterf
#undef nextafterl
#undef nexttoward
#undef nexttowardf
#undef nexttowardl
#undef remainder
#undef remainderf
#undef remainderl
#undef remquo
#undef remquof
#undef remquol
#undef rint
#undef rintf
#undef rintl
#undef round
#undef roundf
#undef roundl
#undef scalbln
#undef scalblnf
#undef scalblnl
#undef scalbn
#undef scalbnf
#undef scalbnl
#undef tgamma
#undef tgammaf
#undef tgammal
#undef trunc
#undef truncf
#undef truncl

  // types
  using ::double_t;
  using ::float_t;

  // functions
  using ::acosh;
  using ::acoshf;
  using ::acoshl;

  using ::asinh;
  using ::asinhf;
  using ::asinhl;

  using ::atanh;
  using ::atanhf;
  using ::atanhl;

  using ::cbrt;
  using ::cbrtf;
  using ::cbrtl;

  using ::copysign;
  using ::copysignf;
  using ::copysignl;

  using ::erf;
  using ::erff;
  using ::erfl;

  using ::erfc;
  using ::erfcf;
  using ::erfcl;

  using ::exp2;
  using ::exp2f;
  using ::exp2l;

  using ::expm1;
  using ::expm1f;
  using ::expm1l;

  using ::fdim;
  using ::fdimf;
  using ::fdiml;

  using ::fma;
  using ::fmaf;
  using ::fmal;

  using ::fmax;
  using ::fmaxf;
  using ::fmaxl;

  using ::fmin;
  using ::fminf;
  using ::fminl;

  using ::hypot;
  using ::hypotf;
  using ::hypotl;

  using ::ilogb;
  using ::ilogbf;
  using ::ilogbl;

  using ::lgamma;
  using ::lgammaf;
  using ::lgammal;

#ifndef _GLIBCXX_NO_C99_ROUNDING_FUNCS
  using ::llrint;
  using ::llrintf;
  using ::llrintl;

  using ::llround;
  using ::llroundf;
  using ::llroundl;
#endif

  using ::log1p;
  using ::log1pf;
  using ::log1pl;

  using ::log2;
  using ::log2f;
  using ::log2l;

  using ::logb;
  using ::logbf;
  using ::logbl;

  using ::lrint;
  using ::lrintf;
  using ::lrintl;

  using ::lround;
  using ::lroundf;
  using ::lroundl;

  using ::nan;
  using ::nanf;
  using ::nanl;

  using ::nearbyint;
  using ::nearbyintf;
  using ::nearbyintl;

  using ::nextafter;
  using ::nextafterf;
  using ::nextafterl;

  using ::nexttoward;
  using ::nexttowardf;
  using ::nexttowardl;

  using ::remainder;
  using ::remainderf;
  using ::remainderl;

  using ::remquo;
  using ::remquof;
  using ::remquol;

  using ::rint;
  using ::rintf;
  using ::rintl;

  using ::round;
  using ::roundf;
  using ::roundl;

  using ::scalbln;
  using ::scalblnf;
  using ::scalblnl;

  using ::scalbn;
  using ::scalbnf;
  using ::scalbnl;

  using ::tgamma;
  using ::tgammaf;
  using ::tgammal;

  using ::trunc;
  using ::truncf;
  using ::truncl;

  /// Additional overloads.
#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  acosh(float __x)
  { return __builtin_acoshf(__x); }

  constexpr long double
  acosh(long double __x)
  { return __builtin_acoshl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    acosh(_Tp __x)
    { return __builtin_acosh(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  asinh(float __x)
  { return __builtin_asinhf(__x); }

  constexpr long double
  asinh(long double __x)
  { return __builtin_asinhl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    asinh(_Tp __x)
    { return __builtin_asinh(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  atanh(float __x)
  { return __builtin_atanhf(__x); }

  constexpr long double
  atanh(long double __x)
  { return __builtin_atanhl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    atanh(_Tp __x)
    { return __builtin_atanh(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  cbrt(float __x)
  { return __builtin_cbrtf(__x); }

  constexpr long double
  cbrt(long double __x)
  { return __builtin_cbrtl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    cbrt(_Tp __x)
    { return __builtin_cbrt(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  copysign(float __x, float __y)
  { return __builtin_copysignf(__x, __y); }

  constexpr long double
  copysign(long double __x, long double __y)
  { return __builtin_copysignl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    copysign(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return copysign(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  erf(float __x)
  { return __builtin_erff(__x); }

  constexpr long double
  erf(long double __x)
  { return __builtin_erfl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    erf(_Tp __x)
    { return __builtin_erf(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  erfc(float __x)
  { return __builtin_erfcf(__x); }

  constexpr long double
  erfc(long double __x)
  { return __builtin_erfcl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    erfc(_Tp __x)
    { return __builtin_erfc(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  exp2(float __x)
  { return __builtin_exp2f(__x); }

  constexpr long double
  exp2(long double __x)
  { return __builtin_exp2l(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    exp2(_Tp __x)
    { return __builtin_exp2(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  expm1(float __x)
  { return __builtin_expm1f(__x); }

  constexpr long double
  expm1(long double __x)
  { return __builtin_expm1l(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    expm1(_Tp __x)
    { return __builtin_expm1(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  fdim(float __x, float __y)
  { return __builtin_fdimf(__x, __y); }

  constexpr long double
  fdim(long double __x, long double __y)
  { return __builtin_fdiml(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    fdim(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return fdim(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  fma(float __x, float __y, float __z)
  { return __builtin_fmaf(__x, __y, __z); }

  constexpr long double
  fma(long double __x, long double __y, long double __z)
  { return __builtin_fmal(__x, __y, __z); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up, typename _Vp&gt;
    constexpr typename __gnu_cxx::__promote_3&lt;_Tp, _Up, _Vp&gt;::__type
    fma(_Tp __x, _Up __y, _Vp __z)
    {
      typedef typename __gnu_cxx::__promote_3&lt;_Tp, _Up, _Vp&gt;::__type __type;
      return fma(__type(__x), __type(__y), __type(__z));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  fmax(float __x, float __y)
  { return __builtin_fmaxf(__x, __y); }

  constexpr long double
  fmax(long double __x, long double __y)
  { return __builtin_fmaxl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    fmax(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return fmax(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  fmin(float __x, float __y)
  { return __builtin_fminf(__x, __y); }

  constexpr long double
  fmin(long double __x, long double __y)
  { return __builtin_fminl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    fmin(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return fmin(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  hypot(float __x, float __y)
  { return __builtin_hypotf(__x, __y); }

  constexpr long double
  hypot(long double __x, long double __y)
  { return __builtin_hypotl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    hypot(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return hypot(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr int
  ilogb(float __x)
  { return __builtin_ilogbf(__x); }

  constexpr int
  ilogb(long double __x)
  { return __builtin_ilogbl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr
    typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                    int&gt;::__type
    ilogb(_Tp __x)
    { return __builtin_ilogb(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  lgamma(float __x)
  { return __builtin_lgammaf(__x); }

  constexpr long double
  lgamma(long double __x)
  { return __builtin_lgammal(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    lgamma(_Tp __x)
    { return __builtin_lgamma(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr long long
  llrint(float __x)
  { return __builtin_llrintf(__x); }

  constexpr long long
  llrint(long double __x)
  { return __builtin_llrintl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              long long&gt;::__type
    llrint(_Tp __x)
    { return __builtin_llrint(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr long long
  llround(float __x)
  { return __builtin_llroundf(__x); }

  constexpr long long
  llround(long double __x)
  { return __builtin_llroundl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              long long&gt;::__type
    llround(_Tp __x)
    { return __builtin_llround(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  log1p(float __x)
  { return __builtin_log1pf(__x); }

  constexpr long double
  log1p(long double __x)
  { return __builtin_log1pl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    log1p(_Tp __x)
    { return __builtin_log1p(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  // DR 568.
  constexpr float
  log2(float __x)
  { return __builtin_log2f(__x); }

  constexpr long double
  log2(long double __x)
  { return __builtin_log2l(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    log2(_Tp __x)
    { return __builtin_log2(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  logb(float __x)
  { return __builtin_logbf(__x); }

  constexpr long double
  logb(long double __x)
  { return __builtin_logbl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    logb(_Tp __x)
    { return __builtin_logb(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr long
  lrint(float __x)
  { return __builtin_lrintf(__x); }

  constexpr long
  lrint(long double __x)
  { return __builtin_lrintl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              long&gt;::__type
    lrint(_Tp __x)
    { return __builtin_lrint(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr long
  lround(float __x)
  { return __builtin_lroundf(__x); }

  constexpr long
  lround(long double __x)
  { return __builtin_lroundl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              long&gt;::__type
    lround(_Tp __x)
    { return __builtin_lround(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  nearbyint(float __x)
  { return __builtin_nearbyintf(__x); }

  constexpr long double
  nearbyint(long double __x)
  { return __builtin_nearbyintl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    nearbyint(_Tp __x)
    { return __builtin_nearbyint(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  nextafter(float __x, float __y)
  { return __builtin_nextafterf(__x, __y); }

  constexpr long double
  nextafter(long double __x, long double __y)
  { return __builtin_nextafterl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    nextafter(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return nextafter(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  nexttoward(float __x, long double __y)
  { return __builtin_nexttowardf(__x, __y); }

  constexpr long double
  nexttoward(long double __x, long double __y)
  { return __builtin_nexttowardl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    nexttoward(_Tp __x, long double __y)
    { return __builtin_nexttoward(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  remainder(float __x, float __y)
  { return __builtin_remainderf(__x, __y); }

  constexpr long double
  remainder(long double __x, long double __y)
  { return __builtin_remainderl(__x, __y); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    constexpr typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    remainder(_Tp __x, _Up __y)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return remainder(__type(__x), __type(__y));
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  inline float
  remquo(float __x, float __y, int* __pquo)
  { return __builtin_remquof(__x, __y, __pquo); }

  inline long double
  remquo(long double __x, long double __y, int* __pquo)
  { return __builtin_remquol(__x, __y, __pquo); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp, typename _Up&gt;
    inline typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type
    remquo(_Tp __x, _Up __y, int* __pquo)
    {
      typedef typename __gnu_cxx::__promote_2&lt;_Tp, _Up&gt;::__type __type;
      return remquo(__type(__x), __type(__y), __pquo);
    }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  rint(float __x)
  { return __builtin_rintf(__x); }

  constexpr long double
  rint(long double __x)
  { return __builtin_rintl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    rint(_Tp __x)
    { return __builtin_rint(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  round(float __x)
  { return __builtin_roundf(__x); }

  constexpr long double
  round(long double __x)
  { return __builtin_roundl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    round(_Tp __x)
    { return __builtin_round(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  scalbln(float __x, long __ex)
  { return __builtin_scalblnf(__x, __ex); }

  constexpr long double
  scalbln(long double __x, long __ex)
  { return __builtin_scalblnl(__x, __ex); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    scalbln(_Tp __x, long __ex)
    { return __builtin_scalbln(__x, __ex); }
#endif
 
#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  scalbn(float __x, int __ex)
  { return __builtin_scalbnf(__x, __ex); }

  constexpr long double
  scalbn(long double __x, int __ex)
  { return __builtin_scalbnl(__x, __ex); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    scalbn(_Tp __x, int __ex)
    { return __builtin_scalbn(__x, __ex); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  tgamma(float __x)
  { return __builtin_tgammaf(__x); }

  constexpr long double
  tgamma(long double __x)
  { return __builtin_tgammal(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    tgamma(_Tp __x)
    { return __builtin_tgamma(__x); }
#endif
 
#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_FP
  constexpr float
  trunc(float __x)
  { return __builtin_truncf(__x); }

  constexpr long double
  trunc(long double __x)
  { return __builtin_truncl(__x); }
#endif

#ifndef __CORRECT_ISO_CPP11_MATH_H_PROTO_INT
  template&lt;typename _Tp&gt;
    constexpr typename __gnu_cxx::__enable_if&lt;__is_integer&lt;_Tp&gt;::__value, 
                                              double&gt;::__type
    trunc(_Tp __x)
    { return __builtin_trunc(__x); }
#endif

#endif // _GLIBCXX_USE_C99_MATH_TR1
#endif // C++11

#if __cplusplus &gt; 201402L

  // [c.math.hypot3], three-dimensional hypotenuse
#define __cpp_lib_hypot 201603

  template&lt;typename _Tp&gt;
    inline _Tp
    __hypot3(_Tp __x, _Tp __y, _Tp __z)
    {
      __x = std::abs(__x);
      __y = std::abs(__y);
      __z = std::abs(__z);
      if (_Tp __a = __x &lt; __y ? __y &lt; __z ? __z : __y : __x &lt; __z ? __z : __x)
	return __a * std::sqrt((__x / __a) * (__x / __a)
			       + (__y / __a) * (__y / __a)
			       + (__z / __a) * (__z / __a));
      else
	return {};
    }

  inline float
  hypot(float __x, float __y, float __z)
  { return std::__hypot3&lt;float&gt;(__x, __y, __z); }

  inline double
  hypot(double __x, double __y, double __z)
  { return std::__hypot3&lt;double&gt;(__x, __y, __z); }

  inline long double
  hypot(long double __x, long double __y, long double __z)
  { return std::__hypot3&lt;long double&gt;(__x, __y, __z); }

  template&lt;typename _Tp, typename _Up, typename _Vp&gt;
    typename __gnu_cxx::__promote_3&lt;_Tp, _Up, _Vp&gt;::__type
    hypot(_Tp __x, _Up __y, _Vp __z)
    {
      using __type = typename __gnu_cxx::__promote_3&lt;_Tp, _Up, _Vp&gt;::__type;
      return std::__hypot3&lt;__type&gt;(__x, __y, __z);
    }
#endif // C++17

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#if _GLIBCXX_USE_STD_SPEC_FUNCS
#  include &lt;bits/specfun.h&gt;
#endif

} // extern &quot;C++&quot;

#endif
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