<iosfwd>

Declara referências de encaminhamento para vários modelos de classe usados por meio de iostreams. Todas esses modelos de classe são definidos em outros cabeçalhos padrão. Inclua explicitamente esse cabeçalho somente quando precisar de uma de suas declarações, mas não de sua definição.

Sintaxe

#include <iosfwd>

Typedefs

typedef T1 streamoff;
typedef T2 streamsize;
typedef fpos streampos;

// char TYPE DEFINITIONS
typedef basic_ios<char, char_traits<char>> ios;
typedef basic_streambuf<char, char_traits<char>> streambuf;
typedef basic_istream<char, char_traits<char>> istream;
typedef basic_ostream<char, char_traits<char>> ostream;
typedef basic_iostream<char, char_traits<char>> iostream;
typedef basic_stringbuf<char, char_traits<char>> stringbuf;
typedef basic_istringstream<char, char_traits<char>> istringstream;
typedef basic_ostringstream<char, char_traits<char>> ostringstream;
typedef basic_stringstream<char, char_traits<char>> stringstream;
typedef basic_filebuf<char, char_traits<char>> filebuf;
typedef basic_ifstream<char, char_traits<char>> ifstream;
typedef basic_ofstream<char, char_traits<char>> ofstream;
typedef basic_fstream<char, char_traits<char>> fstream;

// wchar_t TYPE DEFINITIONS
typedef basic_ios<wchar_t, char_traits<wchar_t>> wios;
typedef basic_streambuf<wchar_t, char_traits<wchar_t>> wstreambuf;
typedef basic_istream<wchar_t, char_traits<wchar_t>> wistream;
typedef basic_ostream<wchar_t, char_traits<wchar_t>> wostream;
typedef basic_iostream<wchar_t, char_traits<wchar_t>> wiostream;
typedef basic_stringbuf<wchar_t, char_traits<wchar_t>> wstringbuf;
typedef basic_istringstream<wchar_t, char_traits<wchar_t>> wistringstream;
typedef basic_ostringstream<wchar_t, char_traits<wchar_t>> wostringstream;
typedef basic_stringstream<wchar_t, char_traits<wchar_t>> wstringstream;
typedef basic_filebuf<wchar_t, char_traits<wchar_t>> wfilebuf;
typedef basic_ifstream<wchar_t, char_traits<wchar_t>> wifstream;
typedef basic_ofstream<wchar_t, char_traits<wchar_t>> wofstream;
typedef basic_fstream<wchar_t, char_traits<wchar_t>> wfstream;

Enviar declarações e modelos de classe

template <class _Statetype>
class fpos;

template <class Elem>;
class char_traits;

class char_traits<char>;

class char_traits<wchar_t>;

template <class T>
class allocator;

class ios_base;

template <class Elem, class Tr = char_traits<Elem>>
class basic_ios;

template <class Elem, class Tr = char_traits<Elem>>
class istreambuf_iterator;

template <class Elem, class Tr = char_traits<Elem>>
class ostreambuf_iterator;

template <class Elem, class Tr = char_traits<Elem>>
class basic_streambuf;

template <class Elem, class Tr = char_traits<Elem>>
class basic_istream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_ostream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_iostream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_stringbuf;

template <class Elem, class Tr = char_traits<Elem>>
class basic_istringstream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_ostringstream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_stringstream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_filebuf;

template <class Elem, class Tr = char_traits<Elem>>
class basic_ifstream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_ofstream;

template <class Elem, class Tr = char_traits<Elem>>
class basic_fstream;

Confira também

Referência de Arquivos de Cabeçalho
Acesso Thread-Safe na Biblioteca Padrão C++
Programação de iostream
Convenções de iostreams