13.28 <iosfwd>
The <iosfwd> header provides forward declarations of the various I/O-related classes and templates. The forward declarations are incomplete type declarations. (Read about complete and incomplete types in Chapter 6.) By using <iosfwd> you can sometimes avoid including the complete definitions of the I/O classes, and thereby save some compilation time.
It is always safe to include <iosfwd> and any of the other I/O headers, even if they both declare the same type.
Because <iosfwd> does not provide any complete type declarations, this section contains only Table 13-18, which lists each type name with a reference to the header (if any) that is required for the complete type.
|
Type declaration |
Header |
|---|---|
|
template<typename T> class allocator |
<memory> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_filebuf |
<fstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_fstream |
<fstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_ifstream |
<fstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_ios |
<ios> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_iostream |
<istream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_istream |
<istream> |
|
template<typename charT, typename traits=char_traits<charT>, typename Alloc = allocator<charT> > class basic_istringstream |
<sstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_ofstream |
<fstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_ostream |
<ostream> |
|
template<typename charT, typename traits=char_traits<charT>, typename Alloc = allocator<charT> > class basic_ostringstream |
<sstream> |
|
template<typename charT, typename traits=char_traits<charT> > class basic_streambuf |
<streambuf> |
|
template<typename charT, typename traits=char_traits<charT>, typename Alloc = allocator<charT> > class basic_stringbuf |
<sstream> |
|
template<typename charT, typename traits=char_traits<charT>, typename Alloc = allocator<charT> > class basic_stringstream |
<sstream> |
|
template<typename charT> class char_traits |
<string> |
|
template<> class char_traits<char> |
<string> |
|
template<> class char_traits<wchar_t> |
<string> |
|
typedef basic_filebuf<char> filebuf |
<fstream> |
|
template <typename state> class fpos |
<ios> |
|
typedef basic_fstream<char> fstream |
<fstream> |
|
typedef basic_ifstream<char> ifstream |
<fstream> |
|
typedef basic_ios<char> ios |
<ios> |
|
typedef basic_iostream<char> iostream |
<istream> |
|
typedef basic_istream<char> istream |
<istream> |
|
template<typename charT, typename traits=char_traits<charT> > class istreambuf_iterator |
<iterator> |
|
typedef basic_istringstream<char> istringstream |
<sstream> |
|
typedef basic_ofstream<char> ofstream |
<fstream> |
|
typedef basic_ostream<char> ostream |
<ostream> |
|
template<typename charT, typename traits=char_traits<charT> > class ostreambuf_iterator |
<iterator> |
|
typedef basic_ostringstream<char> ostringstream |
<sstream> |
|
typedef basic_streambuf<char> streambuf |
<streambuf> |
|
typedef fpos<char_traits<char>::state_type> streampos |
N/A |
|
typedef basic_stringbuf<char> stringbuf |
<sstream> |
|
typedef basic_stringstream<char> stringstream |
<sstream> |
|
typedef basic_filebuf<wchar_t> wfilebuf |
<fstream> |
|
typedef basic_fstream<wchar_t> wfstream |
<fstream> |
|
typedef basic_ifstream<wchar_t> wifstream |
<fstream> |
|
typedef basic_ios<wchar_t> wios |
<ios> |
|
typedef basic_iostream<wchar_t> wiostream |
<istream> |
|
typedef basic_istream<wchar_t> wistream |
<istream> |
|
typedef basic_istringstream<wchar_t> wistringstream |
<sstream> |
|
typedef basic_ofstream<wchar_t> wofstream |
<fstream> |
|
typedef basic_ostream<wchar_t> wostream |
<ostream> |
|
typedef basic_ostringstream<wchar_t> wostringstream |
<sstream> |
|
typedef basic_streambuf<wchar_t> wstreambuf |
<streambuf> |
|
typedef fpos<char_traits<wchar_t>::state_type> wstreampos |
N/A |
|
typedef basic_stringbuf<wchar_t> wstringbuf |
<sstream> |
|
typedef basic_stringstream<wchar_t> wstringstream |
<sstream> |
