std::ranges::chunk_view<V>::outer-iterator

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< cpp‎ | ranges‎ | chunk view
 
 
Ranges library
Range adaptors
 
std::ranges::chunk_view
Member functions
Classes for input_ranges
Deduction guides
outer-iterator
outer-iterator::value_type
inner-iterator
 
class /*outer-iterator*/
(since C++23)
(exposition only*)

The return type of chunk_view::begin if V models input_range.

Member types

Member type Definition
iterator_concept std::input_iterator_tag
difference_type ranges::range_difference_t<V>

Data members

Member object Definition
parent_ (private) A pointer to the "parent object" of type ranges::chunk_view*
(exposition-only member object*)

Member functions

constructs an iterator
(public member function)
(C++23)
move assigns another iterator
(public member function)
(C++23)
accesses the element
(public member function)
increments the iterator
(public member function)

Non-member functions

compares the iterator with default sentinel
(function)
(C++23)
calculates the number of chunks remaining
(function)

Nested classes

the value type of /*output-iterator*/
(public member class)

Example

#include <iostream>
#include <iterator>
#include <ranges>
#include <sstream>
 
int main()
{
    const std::string source{"ABCDEFGHIJ"};
 
    auto letters = std::istringstream{source};
    auto chunks = std::ranges::istream_view<char>(letters)
                | std::views::chunk(4);
 
    for (auto outer_iter = chunks.begin(); outer_iter != std::default_sentinel;
         ++outer_iter)
    {
        auto chunk = *outer_iter; // chunk is an object of type
                                  // chunk_view::outer_iterator::value_type
        std::cout << '[';
        for (auto inner_iter = chunk.begin(); inner_iter != std::default_sentinel;
             ++inner_iter)
            std::cout << *inner_iter;
        std::cout << "] ";
    }
    std::cout << '\n';
 
    // The same output using range-for loops
    auto letters2 = std::istringstream{source};
    auto chunks2 = std::ranges::istream_view<char>(letters2)
                 | std::views::chunk(4);
    for (auto chunk : chunks2)
    {
        std::cout << '[';
        for (auto ch : chunk)
            std::cout << ch;
        std::cout << "] ";
    }
    std::cout << '\n';
}

Output:

[ABCD] [EFGH] [IJ]
[ABCD] [EFGH] [IJ]

References

  • C++23 standard (ISO/IEC 14882:2024):
  • 26.7.28.3 Class chunk_view::outer-iterator [range.chunk.outer.iter]

See also