std::ranges::take_while_view<V,Pred>::begin
constexpr auto begin() requires (!__SimpleView<V>); |
(1) | (since C++20) |
constexpr auto begin() const requires
ranges::range<const V> &&
std::indirect_unary_predicate<const Pred, ranges::iterator_t<const V>>; |
(2) | (since C++20) |
Returns an iterator to the first element of the view. Effectively calls ranges::begin on the underlying view.
Overload (1) does not participate in overload resolution if V is a simple view (that is, if V and const V are views with the same iterator and sentinel types).
Parameters
(none).
Return value
ranges::begin(base_), where base_ is the underlying view.
Example
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 3450 | C++20 | the const overload might return an iterator non-comparable to the sentinel |
constrained |
See also
|
(C++20)
|
returns a sentinel representing the end (public member function) |
|
(C++20)
|
compares a sentinel with an iterator returned from take_while_view::begin (function) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/ranges/take_while_view/begin
