std::istream_iterator

 

C++

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Libreria di Utilità

Stringhe

Contenitori

Algoritmi

Iteratori

Libreria matematca

Input/output

Localizzazione

Espressioni regolari(C++11)

Operazioni atomicche(C++11)

Multithreading(C++11)

 

Biblioteca Iterator

Primitive iteratori Original: Iterator primitives The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
iterator_traits
input_iterator_tag output_iterator_tag forward_iterator_tag bidirectional_iterator_tag random_access_iterator_tag
iterator
Adattatori iteratori Original: Iterator adaptors The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
reverse_iterator
move_iterator (C++11) back_insert_iterator front_insert_iterator insert_iterator	make_move_iterator (C++11) back_inserter front_inserter inserter
Flusso iteratori Original: Stream iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
istream_iterator
ostream_iterator
istreambuf_iterator
ostreambuf_iterator
Operazioni di iteratori Original: Iterator operations The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
advance
distance
prev (C++11)
next (C++11)
Intervallo accesso Original: Range access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
begin (C++11)
end (C++11)

 

std::istream_iterator

Membri funzioni 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.

istream_iterator::istream_iterator

istream_iterator::operator* istream_iterator::operator->

istream_iterator::operator++ istream_iterator::operator++(int)

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

operator== operator!=

 

Elemento definito nell'header <iterator>
template<class T,           class CharT =char,           class Traits =std::char_traits<CharT>,           class Distance =std::ptrdiff_t> class istream_iterator:publicstd::iterator<std::input_iterator_tag,                                              T, Distance, const T*, const T&>

std::istream_iterator è un passaggio singolo iteratore di input che legge gli oggetti successivi di tipo T dall'oggetto std::basic_istream per cui è stata costruita, chiamando il operator>> appropriato. L'operazione di lettura reale viene eseguita quando l'iteratore non viene incrementato, quando è dereferenziato. Il primo oggetto può essere letto quando l'iteratore è costruito o quando la dereferenziazione primo fatto. In caso contrario, dereferenziare solo restituisce una copia dell'oggetto più letto di recente.

Original:

std::istream_iterator is a single-pass input iterator that reads successive objects of type T from the std::basic_istream object for which it was constructed, by calling the appropriate operator>>. The actual read operation is performed when the iterator is incremented, not when it is dereferenced. The first object may be read when the iterator is constructed or when the first dereferencing is done. Otherwise, dereferencing only returns a copy of the most recently read object.

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L'impostazione predefinita-costruito std::istream_iterator è conosciuta come la fine flusso di iteratore. Quando un std::istream_iterator valida raggiunge la fine del flusso sottostante, diventa uguale al fine flusso iteratore. Dereferenziazione o incrementarlo richiede ulteriori comportamento indefinito.

Original:

The default-constructed std::istream_iterator is known as the end-of-stream iterator. When a valid std::istream_iterator reaches the end of the underlying stream, it becomes equal to the end-of-stream iterator. Dereferencing or incrementing it further invokes undefined behavior.

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Una tipica implementazione di std::istream_iterator tiene due membri di dati: un puntatore all'oggetto std::basic_istream associato e il valore più letto di recente di tipo T.

Original:

A typical implementation of std::istream_iterator holds two data members: a pointer to the associated std::basic_istream object and the most recently read value of type T.

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Durante la lettura di caratteri, std::istreambuf_iterator è più efficiente, dato che evita il sovraccarico di costruire e distruggendo l'oggetto sentinella una volta per carattere.

Original:

When reading characters, std::istreambuf_iterator is more efficient, since it avoids the overhead of constructing and destructing the sentry object once per character.

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Membri tipi

Membro tipo Original: Member type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition
char_type	CharT
traits_type	Traits
istream_type	std::basic_istream<CharT, Traits>

Membri funzioni

(costruttore)	costruisce un nuovo istream_iterator Original: constructs a new istream_iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
(destructor) (dichiarato in modo implicito)	destructs an istream_iterator, including the cached value (metodo pubblico)
operator* operator->	ottiene una copia della corrente element accesses membro dell'elemento corrente Original: obtains a copy of the current element accesses a member of the current element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)
operator++ operator++(int)	fa avanzare il istream_iterator Original: advances the istream_iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (metodo pubblico)

Non membri funzioni

operator== operator!=	confronta due istream_iterators Original: compares two istream_iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello)

Inherited from std::iterator

Member types

Membro tipo Original: Member type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.	Definition
value_type	T
difference_type	Distance
pointer	const T*
reference	const T&
iterator_category	std::input_iterator_tag

Esempio

#include <iostream>#include <sstream>#include <iterator>#include <numeric>   int main(){std::istringstream str("0.1 0.2 0.3 0.4");std::partial_sum(std::istream_iterator<double>(str), std::istream_iterator<double>(), std::ostream_iterator<double>(std::cout, " "));}

Output:

0.1 0.3 0.6 1

Vedi anche

ostream_iterator	uscita iteratore che scrive std::basic_ostream Original: output iterator that writes to std::basic_ostream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)
istreambuf_iterator	iteratore di input che legge da std::basic_streambuf Original: input iterator that reads from std::basic_streambuf The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe template)