std::unitbuf, std::nounitbuf
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| Definido no cabeçalho <ios>
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| std::ios_base& unitbuf( std::ios_base& str ); |
(1) | |
| std::ios_base& nounitbuf( std::ios_base& str ); |
(2) | |
Habilita ou desabilita a lavagem automática do fluxo de saída após qualquer operação de saída. Não tem efeito sobre entrada.
1) Original:
Enables or disables automatic flushing of the output stream after any output operation. Has no effect on input.
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permite a bandeira
2) unitbuf no str fluxo, como se chamando str.setf(std::ios_base::unitbuf)Original:
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desabilita a bandeira
unitbuf no str fluxo, como se chamando str.unsetf(std::ios_base::unitbuf)Original:
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Trata-se de um manipulador de I / O, que pode ser chamada com uma indicação tal como para qualquer out << std::unitbuf
out de std::basic_ostream tipo ou com uma indicação tal como para qualquer in >> std::unitbuf in de std::basic_istream tipo.Original:
This is an I/O manipulator, it may be called with an expression such as out << std::unitbuf for any
out of type std::basic_ostream or with an expression such as in >> std::unitbuf for any in of type std::basic_istream.The text has been machine-translated via Google Translate.
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Índice |
[editar] Notas
A lavagem é realizada no processo de destruição do objeto std::basic_ostream::sentry, que chama str.rdbuf()->pubsync() se str.flags() & std::ios_base::unitbuf == true.
Original:
Flushing is performed in the destructor of the std::basic_ostream::sentry object, which calls str.rdbuf()->pubsync() if str.flags() & std::ios_base::unitbuf == true.
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Os objetos de saída padrão std::cerr e std::wcerr têm seu bit
unitbuf definido por padrão.Original:
The standard output objects std::cerr and std::wcerr have their
unitbuf bit set by default.The text has been machine-translated via Google Translate.
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[editar] Parâmetros
| str | - | referência ao fluxo de E / S
Original: reference to I/O stream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[editar] Valor de retorno
str (referência ao fluxo após a manipulação)Original:
str (reference to the stream after manipulation)The text has been machine-translated via Google Translate.
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[editar] Exemplo
Sem unitbuf std :: ou outro esvaziamento explícito, a saída é o mesmo, mas não aparecem em tempo real .
Original:
Without std::unitbuf or another explicit flush, the output is the same, but does not appear in real time.
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#include <iostream> #include <chrono> template<typename Diff> void log_progress(Diff d) { std::cout << "..(" << std::chrono::duration_cast<std::chrono::milliseconds>(d).count() << " ms).."; } int main() { volatile int sink=0; std::cout << std::unitbuf; // enable automatic flushing auto t1 = std::chrono::high_resolution_clock::now(); for(int j=0; j<5; ++j) { for(int n=0; n<10000; ++n) for(int m=0; m<20000; ++m) sink += m*n; // do some work auto now = std::chrono::high_resolution_clock::now(); log_progress(now - t1); } std::cout << '\n'; }
Saída:
..(450 ms)....(902 ms)....(1352 ms)....(1802 ms)....(2252 ms)..
[editar] Veja também
| libera o fluxo de saída Original: flushes the output stream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
| saídas '\n' e libera o fluxo de saída Original: outputs '\n' and flushes the output stream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (modelo de função) | |
