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).



Return value

ranges::begin(base_), where base_ is the underlying view.


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

returns a sentinel representing the end
(public member function)
compares a sentinel with an iterator returned from take_while_view::begin

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