constexpr auto size()
requires ranges::sized_range</*InnerView*/>;
| (1) | (since C++23) |
constexpr auto size() const
requires ranges::sized_range<const /*InnerView*/>
| (2) | (since C++23) |
Returns the number of elements in the zip_transform_view. Provided only if each underlying (adapted) range satisfies sized_range.
return zip_.size();.(none).
The number of elements, which is the minimum size among all sizes of adapted views.
#include <algorithm>
#include <cassert>
#include <deque>
#include <forward_list>
#include <functional>
#include <iostream>
#include <ranges>
#include <vector>
int main()
{
auto x = std::vector{1, 2, 3, 4, 5};
auto y = std::deque<short>{10, 20, 30};
auto z = std::forward_list{100., 200.};
auto v1 = std::views::zip_transform(std::plus, x, y);
assert(v1.size() == std::min(x.size(), y.size()));
assert(v1.size() == 3);
for (int i : v1) std::cout << i << '\n';
[[maybe_unused]] auto v2 = std::views::zip_transform(std::plus, x, z);
// auto sz = v2.size(); // Error, v2 does not have size():
static_assert(not std::ranges::sized_range<decltype(z)>);
}Output:
11 22 33
|
(C++20) | returns an integer equal to the size of a range (customization point object) |
|
(C++20) | returns a signed integer equal to the size of a range (customization point object) |
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