10b57cec5SDimitry Andric// -*- C++ -*- 2*349cc55cSDimitry Andric//===----------------------------------------------------------------------===// 30b57cec5SDimitry Andric// 40b57cec5SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 50b57cec5SDimitry Andric// See https://llvm.org/LICENSE.txt for license information. 60b57cec5SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 70b57cec5SDimitry Andric// 80b57cec5SDimitry Andric//===----------------------------------------------------------------------===// 90b57cec5SDimitry Andric 100b57cec5SDimitry Andric#ifndef _LIBCPP_IOSFWD 110b57cec5SDimitry Andric#define _LIBCPP_IOSFWD 120b57cec5SDimitry Andric 130b57cec5SDimitry Andric/* 140b57cec5SDimitry Andric iosfwd synopsis 150b57cec5SDimitry Andric 160b57cec5SDimitry Andricnamespace std 170b57cec5SDimitry Andric{ 180b57cec5SDimitry Andric 190b57cec5SDimitry Andrictemplate<class charT> struct char_traits; 200b57cec5SDimitry Andrictemplate<> struct char_traits<char>; 210b57cec5SDimitry Andrictemplate<> struct char_traits<char8_t>; // C++20 220b57cec5SDimitry Andrictemplate<> struct char_traits<char16_t>; 230b57cec5SDimitry Andrictemplate<> struct char_traits<char32_t>; 240b57cec5SDimitry Andrictemplate<> struct char_traits<wchar_t>; 250b57cec5SDimitry Andric 260b57cec5SDimitry Andrictemplate<class T> class allocator; 270b57cec5SDimitry Andric 280b57cec5SDimitry Andricclass ios_base; 290b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_ios; 300b57cec5SDimitry Andric 310b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_streambuf; 320b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_istream; 330b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_ostream; 340b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_iostream; 350b57cec5SDimitry Andric 360b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> > 370b57cec5SDimitry Andric class basic_stringbuf; 380b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> > 390b57cec5SDimitry Andric class basic_istringstream; 400b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> > 410b57cec5SDimitry Andric class basic_ostringstream; 420b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> > 430b57cec5SDimitry Andric class basic_stringstream; 440b57cec5SDimitry Andric 450b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_filebuf; 460b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_ifstream; 470b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_ofstream; 480b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class basic_fstream; 490b57cec5SDimitry Andric 500b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class istreambuf_iterator; 510b57cec5SDimitry Andrictemplate <class charT, class traits = char_traits<charT> > class ostreambuf_iterator; 520b57cec5SDimitry Andric 530b57cec5SDimitry Andrictypedef basic_ios<char> ios; 540b57cec5SDimitry Andrictypedef basic_ios<wchar_t> wios; 550b57cec5SDimitry Andric 560b57cec5SDimitry Andrictypedef basic_streambuf<char> streambuf; 570b57cec5SDimitry Andrictypedef basic_istream<char> istream; 580b57cec5SDimitry Andrictypedef basic_ostream<char> ostream; 590b57cec5SDimitry Andrictypedef basic_iostream<char> iostream; 600b57cec5SDimitry Andric 610b57cec5SDimitry Andrictypedef basic_stringbuf<char> stringbuf; 620b57cec5SDimitry Andrictypedef basic_istringstream<char> istringstream; 630b57cec5SDimitry Andrictypedef basic_ostringstream<char> ostringstream; 640b57cec5SDimitry Andrictypedef basic_stringstream<char> stringstream; 650b57cec5SDimitry Andric 660b57cec5SDimitry Andrictypedef basic_filebuf<char> filebuf; 670b57cec5SDimitry Andrictypedef basic_ifstream<char> ifstream; 680b57cec5SDimitry Andrictypedef basic_ofstream<char> ofstream; 690b57cec5SDimitry Andrictypedef basic_fstream<char> fstream; 700b57cec5SDimitry Andric 710b57cec5SDimitry Andrictypedef basic_streambuf<wchar_t> wstreambuf; 720b57cec5SDimitry Andrictypedef basic_istream<wchar_t> wistream; 730b57cec5SDimitry Andrictypedef basic_ostream<wchar_t> wostream; 740b57cec5SDimitry Andrictypedef basic_iostream<wchar_t> wiostream; 750b57cec5SDimitry Andric 760b57cec5SDimitry Andrictypedef basic_stringbuf<wchar_t> wstringbuf; 770b57cec5SDimitry Andrictypedef basic_istringstream<wchar_t> wistringstream; 780b57cec5SDimitry Andrictypedef basic_ostringstream<wchar_t> wostringstream; 790b57cec5SDimitry Andrictypedef basic_stringstream<wchar_t> wstringstream; 800b57cec5SDimitry Andric 810b57cec5SDimitry Andrictypedef basic_filebuf<wchar_t> wfilebuf; 820b57cec5SDimitry Andrictypedef basic_ifstream<wchar_t> wifstream; 830b57cec5SDimitry Andrictypedef basic_ofstream<wchar_t> wofstream; 840b57cec5SDimitry Andrictypedef basic_fstream<wchar_t> wfstream; 850b57cec5SDimitry Andric 860b57cec5SDimitry Andrictemplate <class state> class fpos; 87fe6060f1SDimitry Andricusing streampos = fpos<char_traits<char>::state_type>; 88fe6060f1SDimitry Andricusing wstreampos = fpos<char_traits<wchar_t>::state_type>; 89fe6060f1SDimitry Andricusing u8streampos = fpos<char_traits<char8_t>::state_type>; // C++20 90fe6060f1SDimitry Andricusing u16streampos = fpos<char_traits<char16_t>::state_type>; 91fe6060f1SDimitry Andricusing u32streampos = fpos<char_traits<char32_t>::state_type>; 920b57cec5SDimitry Andric 930b57cec5SDimitry Andric} // std 940b57cec5SDimitry Andric 950b57cec5SDimitry Andric*/ 960b57cec5SDimitry Andric 970b57cec5SDimitry Andric#include <__config> 98*349cc55cSDimitry Andric#include <__mbstate_t.h> 990b57cec5SDimitry Andric 1000b57cec5SDimitry Andric#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 1010b57cec5SDimitry Andric#pragma GCC system_header 1020b57cec5SDimitry Andric#endif 1030b57cec5SDimitry Andric 1040b57cec5SDimitry Andric_LIBCPP_BEGIN_NAMESPACE_STD 1050b57cec5SDimitry Andric 1060b57cec5SDimitry Andricclass _LIBCPP_TYPE_VIS ios_base; 1070b57cec5SDimitry Andric 1080b57cec5SDimitry Andrictemplate<class _CharT> struct _LIBCPP_TEMPLATE_VIS char_traits; 1090b57cec5SDimitry Andrictemplate<> struct char_traits<char>; 110fe6060f1SDimitry Andric#ifndef _LIBCPP_HAS_NO_CHAR8_T 1110b57cec5SDimitry Andrictemplate<> struct char_traits<char8_t>; 1120b57cec5SDimitry Andric#endif 1130b57cec5SDimitry Andrictemplate<> struct char_traits<char16_t>; 1140b57cec5SDimitry Andrictemplate<> struct char_traits<char32_t>; 115*349cc55cSDimitry Andric#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 1160b57cec5SDimitry Andrictemplate<> struct char_traits<wchar_t>; 117*349cc55cSDimitry Andric#endif 1180b57cec5SDimitry Andric 1190b57cec5SDimitry Andrictemplate<class _Tp> class _LIBCPP_TEMPLATE_VIS allocator; 1200b57cec5SDimitry Andric 1210b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1220b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_ios; 1230b57cec5SDimitry Andric 1240b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1250b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_streambuf; 1260b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1270b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_istream; 1280b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1290b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_ostream; 1300b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1310b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_iostream; 1320b57cec5SDimitry Andric 1330b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT>, 1340b57cec5SDimitry Andric class _Allocator = allocator<_CharT> > 1350b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_stringbuf; 1360b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT>, 1370b57cec5SDimitry Andric class _Allocator = allocator<_CharT> > 1380b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_istringstream; 1390b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT>, 1400b57cec5SDimitry Andric class _Allocator = allocator<_CharT> > 1410b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_ostringstream; 1420b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT>, 1430b57cec5SDimitry Andric class _Allocator = allocator<_CharT> > 1440b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_stringstream; 1450b57cec5SDimitry Andric 1460b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1470b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_filebuf; 1480b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1490b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_ifstream; 1500b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1510b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_ofstream; 1520b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1530b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_fstream; 1540b57cec5SDimitry Andric 1550b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1560b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS istreambuf_iterator; 1570b57cec5SDimitry Andrictemplate <class _CharT, class _Traits = char_traits<_CharT> > 1580b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator; 1590b57cec5SDimitry Andric 1600b57cec5SDimitry Andrictypedef basic_ios<char> ios; 161*349cc55cSDimitry Andric#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 1620b57cec5SDimitry Andrictypedef basic_ios<wchar_t> wios; 163*349cc55cSDimitry Andric#endif 1640b57cec5SDimitry Andric 1650b57cec5SDimitry Andrictypedef basic_streambuf<char> streambuf; 1660b57cec5SDimitry Andrictypedef basic_istream<char> istream; 1670b57cec5SDimitry Andrictypedef basic_ostream<char> ostream; 1680b57cec5SDimitry Andrictypedef basic_iostream<char> iostream; 1690b57cec5SDimitry Andric 1700b57cec5SDimitry Andrictypedef basic_stringbuf<char> stringbuf; 1710b57cec5SDimitry Andrictypedef basic_istringstream<char> istringstream; 1720b57cec5SDimitry Andrictypedef basic_ostringstream<char> ostringstream; 1730b57cec5SDimitry Andrictypedef basic_stringstream<char> stringstream; 1740b57cec5SDimitry Andric 1750b57cec5SDimitry Andrictypedef basic_filebuf<char> filebuf; 1760b57cec5SDimitry Andrictypedef basic_ifstream<char> ifstream; 1770b57cec5SDimitry Andrictypedef basic_ofstream<char> ofstream; 1780b57cec5SDimitry Andrictypedef basic_fstream<char> fstream; 1790b57cec5SDimitry Andric 180*349cc55cSDimitry Andric#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 1810b57cec5SDimitry Andrictypedef basic_streambuf<wchar_t> wstreambuf; 1820b57cec5SDimitry Andrictypedef basic_istream<wchar_t> wistream; 1830b57cec5SDimitry Andrictypedef basic_ostream<wchar_t> wostream; 1840b57cec5SDimitry Andrictypedef basic_iostream<wchar_t> wiostream; 1850b57cec5SDimitry Andric 1860b57cec5SDimitry Andrictypedef basic_stringbuf<wchar_t> wstringbuf; 1870b57cec5SDimitry Andrictypedef basic_istringstream<wchar_t> wistringstream; 1880b57cec5SDimitry Andrictypedef basic_ostringstream<wchar_t> wostringstream; 1890b57cec5SDimitry Andrictypedef basic_stringstream<wchar_t> wstringstream; 1900b57cec5SDimitry Andric 1910b57cec5SDimitry Andrictypedef basic_filebuf<wchar_t> wfilebuf; 1920b57cec5SDimitry Andrictypedef basic_ifstream<wchar_t> wifstream; 1930b57cec5SDimitry Andrictypedef basic_ofstream<wchar_t> wofstream; 1940b57cec5SDimitry Andrictypedef basic_fstream<wchar_t> wfstream; 195*349cc55cSDimitry Andric#endif 1960b57cec5SDimitry Andric 197e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 198*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(ios) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wios)) basic_ios; 199e8d8bef9SDimitry Andric 200e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 201*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(streambuf) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstreambuf)) basic_streambuf; 202e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 203*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(istream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wistream)) basic_istream; 204e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 205*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(ostream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wostream)) basic_ostream; 206e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 207*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(iostream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wiostream)) basic_iostream; 208e8d8bef9SDimitry Andric 209e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits, class _Allocator> 210*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(stringbuf) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstringbuf)) basic_stringbuf; 211e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits, class _Allocator> 212*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(istringstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wistringstream)) basic_istringstream; 213e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits, class _Allocator> 214*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(ostringstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wostringstream)) basic_ostringstream; 215e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits, class _Allocator> 216*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(stringstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstringstream)) basic_stringstream; 217e8d8bef9SDimitry Andric 218e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 219*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(filebuf) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wfilebuf)) basic_filebuf; 220e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 221*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(ifstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wifstream)) basic_ifstream; 222e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 223*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(ofstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wofstream)) basic_ofstream; 224e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 225*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(fstream) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wfstream)) basic_fstream; 226e8d8bef9SDimitry Andric 2270b57cec5SDimitry Andrictemplate <class _State> class _LIBCPP_TEMPLATE_VIS fpos; 2280b57cec5SDimitry Andrictypedef fpos<mbstate_t> streampos; 2290b57cec5SDimitry Andrictypedef fpos<mbstate_t> wstreampos; 230fe6060f1SDimitry Andric#ifndef _LIBCPP_HAS_NO_CHAR8_T 2310b57cec5SDimitry Andrictypedef fpos<mbstate_t> u8streampos; 2320b57cec5SDimitry Andric#endif 2330b57cec5SDimitry Andric#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS 2340b57cec5SDimitry Andrictypedef fpos<mbstate_t> u16streampos; 2350b57cec5SDimitry Andrictypedef fpos<mbstate_t> u32streampos; 236*349cc55cSDimitry Andric#endif 2370b57cec5SDimitry Andric 2380b57cec5SDimitry Andric#if defined(_NEWLIB_VERSION) 2390b57cec5SDimitry Andric// On newlib, off_t is 'long int' 2400b57cec5SDimitry Andrictypedef long int streamoff; // for char_traits in <string> 2410b57cec5SDimitry Andric#else 2420b57cec5SDimitry Andrictypedef long long streamoff; // for char_traits in <string> 2430b57cec5SDimitry Andric#endif 2440b57cec5SDimitry Andric 2450b57cec5SDimitry Andrictemplate <class _CharT, // for <stdexcept> 2460b57cec5SDimitry Andric class _Traits = char_traits<_CharT>, 2470b57cec5SDimitry Andric class _Allocator = allocator<_CharT> > 2480b57cec5SDimitry Andric class _LIBCPP_TEMPLATE_VIS basic_string; 2490b57cec5SDimitry Andrictypedef basic_string<char, char_traits<char>, allocator<char> > string; 250*349cc55cSDimitry Andric#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS 2510b57cec5SDimitry Andrictypedef basic_string<wchar_t, char_traits<wchar_t>, allocator<wchar_t> > wstring; 252*349cc55cSDimitry Andric#endif 2530b57cec5SDimitry Andric 254e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits, class _Allocator> 255*349cc55cSDimitry Andric class _LIBCPP_PREFERRED_NAME(string) _LIBCPP_IF_WIDE_CHARACTERS(_LIBCPP_PREFERRED_NAME(wstring)) basic_string; 2560b57cec5SDimitry Andric 2570b57cec5SDimitry Andric// Include other forward declarations here 2580b57cec5SDimitry Andrictemplate <class _Tp, class _Alloc = allocator<_Tp> > 2590b57cec5SDimitry Andricclass _LIBCPP_TEMPLATE_VIS vector; 2600b57cec5SDimitry Andric 261e8d8bef9SDimitry Andrictemplate <class _CharT, class _Traits> 262e8d8bef9SDimitry Andricclass __save_flags 263e8d8bef9SDimitry Andric{ 264e8d8bef9SDimitry Andric typedef basic_ios<_CharT, _Traits> __stream_type; 265e8d8bef9SDimitry Andric typedef typename __stream_type::fmtflags fmtflags; 266e8d8bef9SDimitry Andric 267e8d8bef9SDimitry Andric __stream_type& __stream_; 268e8d8bef9SDimitry Andric fmtflags __fmtflags_; 269e8d8bef9SDimitry Andric _CharT __fill_; 270e8d8bef9SDimitry Andric 271e8d8bef9SDimitry Andric __save_flags(const __save_flags&); 272e8d8bef9SDimitry Andric __save_flags& operator=(const __save_flags&); 273e8d8bef9SDimitry Andricpublic: 274e8d8bef9SDimitry Andric _LIBCPP_INLINE_VISIBILITY 275e8d8bef9SDimitry Andric explicit __save_flags(__stream_type& __stream) 276e8d8bef9SDimitry Andric : __stream_(__stream), 277e8d8bef9SDimitry Andric __fmtflags_(__stream.flags()), 278e8d8bef9SDimitry Andric __fill_(__stream.fill()) 279e8d8bef9SDimitry Andric {} 280e8d8bef9SDimitry Andric _LIBCPP_INLINE_VISIBILITY 281e8d8bef9SDimitry Andric ~__save_flags() 282e8d8bef9SDimitry Andric { 283e8d8bef9SDimitry Andric __stream_.flags(__fmtflags_); 284e8d8bef9SDimitry Andric __stream_.fill(__fill_); 285e8d8bef9SDimitry Andric } 286e8d8bef9SDimitry Andric}; 287e8d8bef9SDimitry Andric 2880b57cec5SDimitry Andric_LIBCPP_END_NAMESPACE_STD 2890b57cec5SDimitry Andric 2900b57cec5SDimitry Andric#endif // _LIBCPP_IOSFWD 291