zZzzZ. — /usr/include/c++/11

Editing: complex.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 complex.h
 *  This is a Standard C++ Library header.
 */

#include <bits/c++config.h>

#if __cplusplus >= 201103L
# include <ccomplex>
#endif

#if __cplusplus >= 201103L && defined(__STRICT_ANSI__)
// For strict modes do not include the C library's <complex.h>, see PR 82417.
#elif _GLIBCXX_HAVE_COMPLEX_H
# include_next <complex.h>
# ifdef _GLIBCXX_COMPLEX
// See PR56111, keep the macro in C++03 if possible.
#  undef complex
# endif
#endif

#ifndef _GLIBCXX_COMPLEX_H
#define _GLIBCXX_COMPLEX_H 1

#endif