C++/iosfwd
< C++
iosfwd 是w:C++标准程式库中的一个w:头文件，定义了C++标准中的文件流输入输出的几个模板类与类型的w:前向声明。
类模板
[编辑]namespace std {
//Defined in header <string>
template<class charT> struct char_traits;
template<> class char_traits<char>;
template<> class char_traits<char16_t>;
template<> class char_traits<char32_t>;
template<> class char_traits<wchar_t>;
//Defined in header <memory>
template<class T> class allocator;
//Defined in header <ios>
template <class charT, class traits=char_traits<charT> > class basic_ios;
template <class charT, class traits=char_traits<charT> > class basic_istream;
template <class charT, class traits=char_traits<charT> > class basic_ostream;
template <class charT, class traits=char_traits<charT> > class basic_iostream;
//Defined in header <streambuf>
template <class charT, class traits=char_traits<charT> > class basic_streambuf;
//Defined in header <sstream>
template <class charT, class traits=char_traits<charT>, class Alloc=allocator<charT> >
class basic_stringbuf;
template <class charT, class traits=char_traits<charT>, class Alloc=allocator<charT> >
class basic_istringstream;
template <class charT, class traits=char_traits<charT>, class Alloc=allocator<charT> >
class basic_ostringstream;
template <class charT, class traits=char_traits<charT>, class Alloc=allocator<charT> >
class basic_stringstream;
//Defined in header <istream>
template <class charT, class traits=char_traits<charT> > class basic_ifstream;
//Defined in header <ostream>
template <class charT, class traits=char_traits<charT> > class basic_ofstream;
//Defined in header <fstream>
template <class charT, class traits=char_traits<charT> > class basic_filebuf;
template <class charT, class traits=char_traits<charT> > class basic_fstream;
template <class charT, class traits=char_traits<charT> > class istreambuf_iterator;
template <class charT, class traits=char_traits<charT> > class ostreambuf_iterator;
//Defined in header <strstream> (deprecated)
class strstreambuf : public std::basic_streambuf<char>;
class istrstream;
class ostrstream;
class strstream;
template<class stateT> class fpos;
typedef basic_ios<char> ios;
typedef basic_streambuf<char> streambuf;
typedef basic_istream<char> istream;
typedef basic_ostream<char> ostream;
typedef basic_iostream<char> iostream;
typedef basic_stringbuf<char> stringbuf;
typedef basic_istringstream<char> istringstream;
typedef basic_ostringstream<char> ostringstream;
typedef basic_stringstream<char> stringstream;
typedef basic_filebuf<char> filebuf;
typedef basic_ifstream<char> ifstream;
typedef basic_ofstream<char> ofstream;
typedef basic_fstream<char> fstream;
typedef basic_ios<wchar_t> wios;
typedef basic_streambuf<wchar_t> wstreambuf;
typedef basic_istream<wchar_t> wistream;
typedef basic_ostream<wchar_t> wostream;
typedef basic_iostream<wchar_t> wiostream;
typedef basic_stringbuf<wchar_t> wstringbuf;
typedef basic_istringstream<wchar_t> wistringstream;
typedef basic_ostringstream<wchar_t> wostringstream;
typedef basic_stringstream<wchar_t> wstringstream;
typedef basic_filebuf<wchar_t> wfilebuf;
typedef basic_ifstream<wchar_t> wifstream;
typedef basic_ofstream<wchar_t> wofstream;
typedef basic_fstream<wchar_t> wfstream;
typedef fpos<mbstate_t> streampos;
typedef fpos<mbstate_t> wstreampos;
}