zZzzZ. — /usr/include/c++/11

Editing: fenv.h

// -*- C++ -*- compatibility header.

// Copyright (C) 2007-2021 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 fenv.h
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_FENV_H
#define _GLIBCXX_FENV_H 1

#pragma GCC system_header

#include <bits/c++config.h>
#if _GLIBCXX_HAVE_FENV_H
# include_next <fenv.h>
#endif

#if __cplusplus >= 201103L

#if _GLIBCXX_USE_C99_FENV_TR1

#undef feclearexcept
#undef fegetexceptflag
#undef feraiseexcept
#undef fesetexceptflag
#undef fetestexcept
#undef fegetround
#undef fesetround
#undef fegetenv
#undef feholdexcept
#undef fesetenv
#undef feupdateenv

namespace std
{
  // types
  using ::fenv_t;
  using ::fexcept_t;

// functions
  using ::feclearexcept;
  using ::fegetexceptflag;
  using ::feraiseexcept;
  using ::fesetexceptflag;
  using ::fetestexcept;

using ::fegetround;
  using ::fesetround;

using ::fegetenv;
  using ::feholdexcept;
  using ::fesetenv;
  using ::feupdateenv;
} // namespace

#endif // _GLIBCXX_USE_C99_FENV_TR1

#endif // C++11

#endif // _GLIBCXX_FENV_H