std::distance

 

C++

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Понятия (концепции)

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Ввод / вывод

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Регулярные выражения (C++11)

Атомарные примитивы (C++11)

Потоки (C++11)

 

Iterator библиотеки

Iterator примитивов 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
Iterator адаптеров 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
Поток итераторы 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
Iterator операций 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)
Диапазон доступа 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)

 

Заголовочный файл <iterator>
template< class InputIt > typename std::iterator_traits<InputIt>::difference_type     distance( InputIt first, InputIt last );

Возвращает количество элементов между first и last.

Original:

Returns the number of elements between first and last.

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Поведение неопределено, если last не доступен из first по (возможно, неоднократно) увеличивая first.

Original:

The behavior is undefined if last is not reachable from first by (possibly repeatedly) incrementing first.

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Параметры

first	-	итератор, указывающий на первый элемент Original: iterator pointing to the first element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
last	-	итератор, указывающий на последний элемент Original: iterator pointing to the last element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Требования, накладываемые на типы
- InputIt должен соответствовать требованиям InputIterator. The operation is more efficient if InputIt additionally meets the requirements of RandomAccessIterator

Возвращаемое значение

Число элементов между first и last.

Original:

The number of elements between first and last.

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Сложность

Линейные.

Original:

Linear.

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Однако, если InputIt дополнительно соответствует требованиям RandomAccessIterator, сложность постоянно.

Original:

However, if InputIt additionally meets the requirements of RandomAccessIterator, complexity is constant.

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Пример

#include <iostream>
#include <iterator>
#include <vector>
 
int main()
{
    std::vector<int> v{ 3, 1, 4 };
 
    auto distance = std::distance(v.begin(), v.end());
 
    std::cout << distance << '\n';
}

Вывод:

3

См. также

advance	авансы итератор на заданное расстояние Original: advances an iterator by given distance The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (функция)