std::ranges::zip_view<Views...>::size
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std::ranges::zip_view
zip_view::size
Member functions
Non-member functions
constexpr auto size()
requires (ranges::sized_range <Views> && ...);
(1)
(since C++23)
requires (ranges::sized_range <Views> && ...);
constexpr auto size() const
requires (ranges::sized_range <const Views> && ...);
(2)
(since C++23)
requires (ranges::sized_range <const Views> && ...);
Returns the number of elements in the zip_view. Provided only if each underlying (adapted) range satisfies sized_range.
Equivalent to:
return std::apply ( [](auto... sizes) { using CT = /*make-unsigned-like-t*/<std::common_type_t <decltype(sizes)...>>; return ranges::min ({CT(sizes)...}); }, /*tuple-transform*/(ranges::size, views_) );
Contents
[edit] Parameters
(none)
[edit] Return value
The number of elements, which is the minimum size among all sizes of adapted views.
[edit] Example
Run this code
#include <algorithm> #include <cassert> #include <deque> #include <forward_list> #include <ranges> #include <vector> int main() { auto x = std::vector {1, 2, 3, 4, 5}; auto y = std::deque {'a', 'b', 'c'}; auto z = std::forward_list {1., 2.}; auto v1 = std::views::zip (x, y); assert (v1.size() == std::min (x.size(), y.size())); assert (v1.size() == 3); [[maybe_unused]] auto v2 = std::views::zip (x, z); // auto sz = v2.size(); // Error, v2 does not have size(): static_assert(not std::ranges::sized_range <decltype(z)>); }