std::istreambuf_iterator — cppreference.com

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Déclaré dans l'en-tête `<iterator>`
`template< class CharT, class Traits = std::char_traits<CharT> > class istreambuf_iterator : public std::iterator< std::input_iterator_tag, CharT, typename Traits::off_type, /* unspecified, usually CharT* */, CharT >`

std::istreambuf_iterator est un itérateur d'entrée en un seul passage qui lit les caractères successifs de l'objet std::basic_streambuf pour lequel il est construit. L'opération de lecture réelle est effectuée lorsque l'itérateur est incrémenté, pas quand il est déréférencé. Le premier caractère peut être lu lorsque l'itérateur est construit ou lorsque le déréférencement premier pas est fait. Dans le cas contraire, le déréférencement ne retourne une copie du personnage le plus lu récemment .

Original:

std::istreambuf_iterator is a single-pass input iterator that reads successive characters from the std::basic_streambuf object for which it was constructed. The actual read operation is performed when the iterator is incremented, not when it is dereferenced. The first character 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 character.

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La valeur par défaut construit std::istreambuf_iterator est connue comme la fin de flux itérateur. Quand un std::istreambuf_iterator valide atteint la fin du flux sous-jacent, il devient égal à l'itérateur de fin de courant. Déréférencement ou l'incrémentant invoque par ailleurs un comportement indéfini .

Original:

The default-constructed std::istreambuf_iterator is known as the end-of-stream iterator. When a valid std::istreambuf_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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std::istreambuf_iterator a un constructeur de copie trivial, un constructeur par défaut constexpr, et un destructeur trivial .

Original:

std::istreambuf_iterator has a trivial copy constructor, a constexpr default constructor, and a trivial destructor.

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Types de membres


Type du membre	Définition

`char_type`	`CharT`

`traits_type`	`Traits`

`int_type`	`typename traits::int_type`

`streambuf_type`	`std::basic_streambuf<CharT, Traits>`

`istream_type`	`std::basic_istream<CharT, Traits>`

Fonctions membres


(constructeur)	construit un nouveau istreambuf_iterator Original: constructs a new istreambuf_iterator 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)

(destructeur) (implicitement déclaré)	destructs an istreambuf_iterator (fonction membre publique)

operator* operator-> (depuis C++11)	obtient une copie du courant character accesses un élément du caractère en cours, si `CharT` a des membres Original: obtains a copy of the current character accesses a member of the current character, if `CharT` has members 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)

operator++ operator++(int)	les progrès de la istreambuf_iterator Original: advances the istreambuf_iterator 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)

equal	si les deux essais sont istreambuf_iterators de fin de courant ou si les deux sont valides Original: tests if both istreambuf_iterators are end-of-stream or if both are valid 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)

Fonctions annexes


	compare deux istreambuf_iterators Original: compares two istreambuf_iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction générique)

Inherited from std::iterator

Member types


Type du membre	Définition

`value_type`	`CharT`

`difference_type`	`Traits::off_type`

`pointer`	`/* unspecified, usually CharT* */`

`reference`	`CharT`

`iterator_category`	`std::input_iterator_tag`

Exemple

#include <vector>
#include <sstream>
#include <iostream>
#include <iterator>
int main()
{
    // typical use case: an input stream represented as a pair of iterators
    std::istringstream in("Hello, world");
    std::vector<char> v( (std::istreambuf_iterator<char>(in)),
                          std::istreambuf_iterator<char>() );
    std::cout << "v has " << v.size() << " bytes. ";
    v.push_back('\0');
    std::cout << "it holds \"" << &v[0] << "\"\n";


    // demonstration of the single-pass nature
    std::istringstream s("abc");
    std::istreambuf_iterator<char> i1(s), i2(s);
    std::cout << "i1 returns " << *i1 << '\n'
              << "i2 returns " << *i2 << '\n';
    ++i1;
    std::cout << "after incrementing i1, but not i2\n"
              << "i1 returns " << *i1 << '\n'
              << "i2 returns " << *i2 << '\n';
    ++i2; // this makes the apparent value of *i2 to jump from 'a' to 'c'
    std::cout << "after incrementing i2, but not i1\n"
              << "i1 returns " << *i1 << '\n'
              << "i2 returns " << *i2 << '\n';

}

Résultat :

v has 12 bytes. it holds "Hello, world"
i1 returns a
i2 returns a
after incrementing i1, but not i2
i1 returns b
i2 returns a
after incrementing i2, but not i1
i1 returns b
i2 returns c

Voir aussi


	itérateur de sortie qui écrit dans std::basic_streambuf Original: output iterator that writes to 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 générique) [edit]

	itérateur d'entrée qui lit std::basic_istream Original: input iterator that reads from std::basic_istream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (classe générique) [edit]