std::ios_base::xalloc

 

C++

Язык

Понятия (концепции)

Утилиты

Строки

Контейнеры

Алгоритмы

Итераторы

Работа с числами

Ввод / вывод

Локализация

Регулярные выражения (C++11)

Атомарные примитивы (C++11)

Потоки (C++11)

 

Библиотеки ввода / вывода

I / O манипуляторов

C-стиль I / O

Буферы 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 (устарело)

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

Абстракций 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

Файл 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

Струнный 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

Массив 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 (устарело)

ostrstream (устарело)

strstream (устарело)

Типы 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

Интерфейс Ошибка категории 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

Член функций 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

Форматирование 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

Языки 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

Внутренние расширяемый массив 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

Разное 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

Член классов 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

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

ios_base::openmode

ios_base::fmtflags

ios_base::iostate

ios_base::seekdir

ios_base::event

ios_base::event_callback

 

static int xalloc();

Возвращает уникальное значение (в рамках всей программы) индекс, который может быть использован для доступа к одному long и один void* элементов в частном хранении по телефону iword() и pword(). Призыв к xalloc не выделяет память.

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.

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

Параметры

(Нет)

Original:

(none)

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

Возвращаемое значение

уникальное целое число, для использования в качестве Pword / iword индекса

Original:

unique integer for use as pword/iword index

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

Пример

Использование базового класса Pword для хранения выполнения идентификации типов объектов, производных от потока .

Original:

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

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

#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';
}

Вывод:

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

См. также

pword	изменяет размер частного хранения при необходимости и доступ к void* элемент по заданному индексу 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. (public функция-член)
iword	изменяет размер частного хранения при необходимости и доступ к long элемент по заданному индексу 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. (public функция-член)