std::ios_base::xalloc

 

C++

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Operaciones de biblioteca Atómica (C++11)

Tema Biblioteca de ayuda (C++11)

 

Entrada / salida de la biblioteca

I / O manipuladores

C-estilo I / O

Buffers Original: Buffers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (obsoleto)

Arroyos Original: Streams The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

Abstracciones Original: Abstractions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base

basic_ios

basic_istream

basic_ostream

basic_iostream

File I / O Original: File I/O The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

basic_ifstream

basic_ofstream

basic_fstream

Cadena de I / O Original: String I/O The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

basic_istringstream

basic_ostringstream

basic_stringstream

Matriz I / O Original: Array I/O The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

istrstream (obsoleto)

ostrstream (obsoleto)

strstream (obsoleto)

Tipos Original: Types The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

streamoff

streamsize

fpos

Error interfaz categoría Original: Error category interface The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

iostream_category (C++11)

io_errc (C++11)

 

std::ios_base

Las funciones miembro Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::ios_base

ios_base::~ios_base

Formato Original: Formatting The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::flags

ios_base::setf

ios_base::unsetf

ios_base::precision

ios_base::width

Locales Original: Locales The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::imbue

ios_base::getloc

Conjunto extensible interior Original: Internal extensible array The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::xalloc

ios_base::iword

ios_base::pword

Varios Original: Miscellaneous The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::register_callback

ios_base::sync_with_stdio

Clases de miembros Original: Member classes The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

ios_base::failure

ios_base::Init

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ios_base::openmode

ios_base::fmtflags

ios_base::iostate

ios_base::seekdir

ios_base::event

ios_base::event_callback

 

static int xalloc();

Devuelve un valor único (en todo el programa) de índice que puede ser utilizado para acceder a uno long y uno void* elementos en el almacenamiento privado llamando iword() y pword(). La llamada a xalloc no asigna memoria .

Original:

Returns an unique (program-wide) index value that can be used to access one long and one void* elements in the private storage by calling iword() and pword(). The call to xalloc does not allocate memory.

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Parámetros

(Ninguno)

Original:

(none)

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Valor de retorno

entero único para su uso como pword / iword índice

Original:

unique integer for use as pword/iword index

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Ejemplo

Utiliza la base de clase de almacenamiento pword para la identificación de tipo en tiempo de ejecución de objetos de flujo derivados .

Original:

Uses base class pword storage for runtime type identification of derived stream objects.

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#include <iostream>
 
template<class charT, class traits = std::char_traits<charT> >
class mystream : public std::basic_ostream<charT, traits>
{
 public:
    static const int xindex;
    mystream(std::basic_ostream<charT, traits>& ostr) :
        std::basic_ostream<charT, traits>(ostr.rdbuf())
    {
         this->pword(xindex) = this;
    }
 
    void myfn()
    {
        *this << "[special handling for mystream]";
    }
};
 
// each specialization of mystream obtains a unique index from xalloc()
template<class charT, class traits>
const int mystream<charT, traits>::xindex = std::ios_base::xalloc();
 
// This I/O manipulator will be able to recognize ostreams that are mystreams
// by looking up the pointer stored in pword
template<class charT, class traits>
std::basic_ostream<charT,traits>& mymanip(std::basic_ostream<charT,traits>& os)
{
 if (os.pword(mystream<charT,traits>::xindex) == &os) 
    static_cast<mystream<charT,traits>&>(os).myfn();
 return os;
}
 
int main()
{
    std::cout << "cout, narrow-character test " << mymanip << '\n';
 
    mystream<char> myout(std::cout);
    myout << "myout, narrow-character test " << mymanip << '\n';
 
    std::wcout << "wcout, wide-character test " << mymanip << '\n';
 
    mystream<wchar_t> mywout(std::wcout);
    mywout << "mywout, wide-character test " << mymanip << '\n';
}

Output:

cout, narrow-character test 
myout, narrow-character test [special handling for mystream]
wcout, wide-character test 
mywout, wide-character test [special handling for mystream]

Ver también

pword	cambia el tamaño del almacenamiento privado si es necesario y el acceso a la void* elemento en el índice especificado Original: resizes the private storage if necessary and access to the void* element at the given index The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (miembro público función)
iword	cambia el tamaño del almacenamiento privado si es necesario y el acceso a la long elemento en el índice especificado Original: resizes the private storage if necessary and access to the long element at the given index The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (miembro público función)