std::ranges::take_view<V>::size

 

C++

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Feature test macros (C++20)

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Concepts library (C++20)

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Ranges library (C++20)

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Ranges library

Range access
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
Range conversions
to (C++23)
Range primitives
range_size_trange_difference_trange_value_trange_reference_t	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)	elements_of (C++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Range factories
empty_viewviews::empty single_viewviews::single	iota_viewviews::iota repeat_viewviews::repeat (C++23)(C++23)	basic_istream_viewviews::istream
Range adaptors
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (C++23)(C++23) filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (C++23)(C++23) lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)
Range generators
std::generator (C++23)
Range adaptor objects
Range adaptor closure objects
range_adaptor_closure (C++23)
Helper items
copyable-box movable-box (until C++23)(C++23)	simple-view non-propagating-cache

 

std::ranges::take_view

Member functions

take_view::take_view (C++20)

take_view::base (C++20)

take_view::begin (C++20)

take_view::end (C++20)

take_view::size (C++20)

Deduction guides

Sentinel

Member functions

take_view::sentinel::sentinel (C++20)

Non-member functions

take_view::sentinel::base (C++20)

operator==(std::counted_iterator,take_view::sentinel) (C++20)

 

constexpr auto size() requires ranges::sized_range<V>;	(1)	(since C++20)
constexpr auto size() const requires ranges::sized_range<const V>;	(2)	(since C++20)

Returns the number of elements, which is the smaller of the count passed to the constructor and the size of the underlying view.

Let base_ be the underlying view, count_ be the number passed to the constructor (​0​ if default constructed). Equivalent to

auto n = ranges::size(base_);
return ranges::min(n, static_cast<decltype(n)>(count_));

Parameters

(none)

Return value

The number of elements.

Example

Run this code

#include <ranges>
#include <iostream>
 
int main()
{
    constexpr int arr[] {1, 2, 3};
 
    for (int i = 0; i != 6; ++i) {
        const auto tv = std::ranges::take_view{arr, i};
        std::cout << tv.size() << ' ';
    }
}

Output:

0 1 2 3 3 3

See also

ranges::size (C++20)	returns an integer equal to the size of a range (customization point object)
ranges::ssize (C++20)	returns a signed integer equal to the size of a range (customization point object)