libstdc++-v3/src/c++11/compatibility-c++0x.cc

// Compatibility symbols for previous versions, C++0x bits -*- C++ -*-

// Copyright (C) 2009-2021 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/>.

#define _GLIBCXX_COMPATIBILITY_CXX0X
#define _GLIBCXX_USE_CXX11_ABI 0
#define error_category error_categoryxx
#define system_category system_categoryxx
#define generic_category generic_categoryxx
#define _V2 _V2xx
#include <string>
#include <system_error>
#include <cstring>
#undef error_category
#undef system_category
#undef generic_category
#undef _V2

#if __cplusplus < 201103L
# error "compatibility-c++0x.cc must be compiled with -std=gnu++0x"
#endif

#ifdef _GLIBCXX_SHARED

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // gcc-4.4.0
  // <mutex> exported std::lock_error
#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
  class lock_error : public exception
  {
  public:
    virtual const char*
    _GLIBCXX_CONST what() const throw();
  };

  const char*
  lock_error::what() const throw()
  { return "std::lock_error"; }
#endif

  // We need these due to the symbols exported since GLIBCXX_3.4.10.
  // See libstdc++/41662 for details.

#ifndef _GLIBCXX_LONG_DOUBLE_COMPAT_IMPL
  template<>
    struct hash<string>
    {
      size_t operator()(string) const;
    };

  size_t
  hash<string>::operator()(string __s) const
  { return _Hash_impl::hash(__s.data(), __s.length()); }

  template<>
    struct hash<const string&>
    {
      size_t operator()(const string&) const;
    };

  size_t
  hash<const string&>::operator()(const string& __s) const
  { return _Hash_impl::hash(__s.data(), __s.length()); }

#ifdef _GLIBCXX_USE_WCHAR_T
  template<>
    struct hash<wstring>
    {
      size_t operator()(wstring) const;
    };

  size_t
  hash<wstring>::operator()(wstring __s) const
  { return _Hash_impl::hash(__s.data(), __s.length() * sizeof(wchar_t)); }

  template<>
    struct hash<const wstring&>
    {
      size_t operator()(const wstring&) const;
    };

  size_t
  hash<const wstring&>::operator()(const wstring& __s) const
  { return _Hash_impl::hash(__s.data(), __s.length() * sizeof(wchar_t)); }
#endif
#endif

  template<>
    struct hash<error_code>
    {
      size_t operator()(error_code) const;
    };

  size_t
  hash<error_code>::operator()(error_code __e) const
  {
    const size_t __tmp = std::_Hash_impl::hash(__e.value());
    return std::_Hash_impl::__hash_combine(&__e.category(), __tmp);
  }

  // gcc-4.7.0
  // <chrono> changes is_monotonic to is_steady.
  namespace chrono
  {
    struct system_clock
    {
      static constexpr bool is_monotonic = false;
    };
    constexpr bool system_clock::is_monotonic;
  } // namespace chrono

  // gcc-5 replaces this with _V2::error_category
  class error_category
  {
  public:
    error_category() noexcept;

    virtual ~error_category();

    error_category(const error_category&) = delete;
    error_category& operator=(const error_category&) = delete;

    virtual const char*
    name() const noexcept = 0;

    virtual string
    message(int) const = 0;

    virtual error_condition
    default_error_condition(int __i) const noexcept;

    virtual bool
    equivalent(int __i, const error_condition& __cond) const noexcept;

    virtual bool
    equivalent(const error_code& __code, int __i) const noexcept;

    bool
    operator<(const error_category& __other) const noexcept
    { return less<const error_category*>()(this, &__other); }

    bool
    operator==(const error_category& __other) const noexcept
    { return this == &__other; }

    bool
    operator!=(const error_category& __other) const noexcept
    { return this != &__other; }
  };

  // gcc-4.9.0
  // LWG 2145 changes this constructor to constexpr i.e. inline
  error_category::error_category() noexcept = default;

  error_category::~error_category() noexcept = default;

  namespace
  {
    using std::string;

    struct generic_error_category : public std::error_category
    {
      virtual const char*
      name() const noexcept
      { return "generic"; }

      virtual string
      message(int i) const
      {
	// XXX locale issues: how does one get or set loc.
	// _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
	return string(strerror(i));
      }
    };

    struct system_error_category : public std::error_category
    {
      virtual const char*
      name() const noexcept
      { return "system"; }

      virtual string
      message(int i) const
      {
	// XXX locale issues: how does one get or set loc.
	// _GLIBCXX_HAVE_STRERROR_L, strerror_l(i, cloc)
	return string(strerror(i));
      }
    };

    const generic_error_category generic_category_instance{};
    const system_error_category system_category_instance{};
  }

  const error_category&
  system_category() noexcept { return system_category_instance; }

  const error_category&
  generic_category() noexcept { return generic_category_instance; }

  namespace _V2
  {
    _GLIBCXX_CONST const error_categoryxx& system_category() noexcept;
    _GLIBCXX_CONST const error_categoryxx& generic_category() noexcept;
  }

  error_condition
  error_category::default_error_condition(int __i) const noexcept
  {
    if (*this == system_category())
      return error_condition(__i, _V2::system_category());
    return error_condition(__i, _V2::generic_category());
  }

  bool
  error_category::equivalent(int __i,
			     const error_condition& __cond) const noexcept
  { return default_error_condition(__i) == __cond; }

  bool
  error_category::equivalent(const error_code& __code, int __i) const noexcept
  {
    if (*this == system_category()
	&& __code.category() == _V2::system_category())
      return __code.value() == __i;
    if (*this == generic_category()
	&& __code.category() == _V2::generic_category())
      return __code.value() == __i;
    return false;
  }

_GLIBCXX_END_NAMESPACE_VERSION
}
#endif