std::iterator_traits

 

C++

Язык

Понятия (концепции)

Утилиты

Строки

Контейнеры

Алгоритмы

Итераторы

Работа с числами

Ввод / вывод

Локализация

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 Iterator> struct iterator_traits;
template< class T > struct iterator_traits<T*>;
template< class T > struct iterator_traits<const T*>;

std::iterator_traits является классом черта, которая предоставляет единый интерфейс к свойствам типов итераторов. Это позволяет реализовать алгоритмы только в терминах итераторов.

Original:

std::iterator_traits is the type trait class that provides uniform interface to the properties of iterator types. This makes it possible to implement algorithms only in terms of iterators.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

Член типов

Член типа 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
difference_type	Iterator::difference_type
value_type	Iterator::value_type
pointer	Iterator::pointer
reference	Iterator::reference
iterator_category	Iterator::iterator_category

Специализации

Этот тип черта может быть специализируется на предоставленные пользователем типы, которые могут быть использованы в качестве итераторов. Стандартная библиотека предоставляет два частичной специализации для типов указателей T *, что позволяет использовать все итератор на основе алгоритмов с сыром указателей.

Original:

This type trait may be specialized for user-provided types that may be used as iterators. The standard library provides two partial specializations for pointer types T*, which makes it possible to use all iterator-based algorithms with raw pointers.

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

T * типах специализации членов

Член типа 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
difference_type	std::ptrdiff_t
value_type	T
pointer	T*
reference	T&
iterator_category	std::random_access_iterator_tag

Const T * типы специализации членов

Член типа 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
difference_type	std::ptrdiff_t
value_type	T
pointer	const T*
reference	const T&
iterator_category	std::random_access_iterator_tag

Пример

общего назначения обратном () для реализации двунаправленные итераторы

Original:

general-purpose reverse() implementation for bidirectional iterators

The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

#include <iostream>
#include <iterator>
#include <vector>
#include <list>
 
template<class BDIter>
void my_reverse(BDIter first, BDIter last)
{
    typename std::iterator_traits<BDIter>::difference_type n = std::distance(first, last);
    --n;
    while(n > 0) {
        typename std::iterator_traits<BDIter>::value_type tmp = *first;
        *first++ = *--last;
        *last = tmp;
        n -= 2;
    }
}
 
int main()
{
    std::vector<int> v{1,2,3,4,5};
    my_reverse(v.begin(), v.end());
    for(int n : v)
        std::cout << n << ' ';
    std::cout << '\n';
 
    std::list<int> l{1,2,3,4,5};
    my_reverse(l.begin(), l.end());
    for(auto n : l)
        std::cout << n << ' ';
    std::cout << '\n';
 
//    std::istreambuf_iterator<char> i1(std::cin), i2;
//    my_reverse(i1, i2); // compilation error
 
}

Вывод:

5 4 3 2 1
5 4 3 2 1

См. также

iterator	основные итератор Original: the basic iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (шаблон класса)
input_iterator_tag output_iterator_tag forward_iterator_tag bidirectional_iterator_tag random_access_iterator_tag	пустым типов класса используется для обозначения категорий итераторов Original: empty class types used to indicate iterator categories The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (класс)