std::ranges::iota_view<W, Bound>::empty
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std::ranges::iota_view
iota_view::empty
constexpr bool empty() const;
(since C++20)
Checks whether the range is empty (i.e. whether the beginning value is the same as the sentinel value).
[edit] Return value
[edit] Example
Run this code
#include <cassert> #include <ranges> int main() { auto a = std::ranges::iota_view <int, int>(); assert (a.empty()); auto b = std::ranges::iota_view (4); assert (!b.empty()); auto c = std::ranges::iota_view (4, 8); assert (!c.empty()); }
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 4001 | C++20 | the inherited member empty function was not always valid
|
empty is always provided
|
[edit] See also
returns the number of elements, provided only if the underlying (adapted) range satisfies
(public member function) [edit]
sized_range (public member function) [edit]