std::ios_base::xalloc
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| static int xalloc(); |
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Retourne une valeur unique (l'ensemble du programme) indice qui peut être utilisé pour accéder à un long et un void* éléments dans le stockage privé en appelant
iword() et pword(). L'appel à xalloc n'alloue pas de mémoire .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.
You can help to correct and verify the translation. Click here for instructions.
Sommaire |
[modifier] Paramètres
(Aucun)
Original:
(none)
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[modifier] Retourne la valeur
entier unique pour une utilisation en tant que motpasse / iword index
Original:
unique integer for use as pword/iword index
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[modifier] Exemple
Utilise la classe de base motpasse de stockage pour l'identification du type d'exécution d'objets de flux dérivés .
Original:
Uses base class pword storage for runtime type identification of derived stream objects.
The text has been machine-translated via Google Translate.
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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'; }
Résultat :
cout, narrow-character test myout, narrow-character test [special handling for mystream] wcout, wide-character test mywout, wide-character test [special handling for mystream]
[modifier] Voir aussi
| redimensionne le stockage privé et le cas échéant un accès à l'élément de void* à l'index donné 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. (fonction membre publique) | |
| redimensionne le stockage privé et le cas échéant un accès à l'élément de long à l'index donné 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. (fonction membre publique) | |
