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std::ranges::drop_while_view<V,Pred>::drop_while_view

drop_while_view() requires std::default_initializable<V> && std::default_initializable<Pred> = default;	(1)	(since C++20)
constexpr drop_while_view( V base, Pred pred );	(2)	(since C++20)

Constructs a drop_while_view.

1) Default constructor. Value-initializes the underlying view and the predicate.

2) Move constructs the underlying view from base and the predicate from pred.

Parameters

base	-	underlying view
pred	-	predicate

Example

#include <array>
#include <iostream>
#include <ranges>
 
int main()
{
    constexpr std::array data{ 0, -1, -2, 3, 1, 4, 1, 5, };
 
    auto view = std::ranges::drop_while_view{
        data, [](int x) { return x <= 0; }
    };
 
    for (int x: view) {
        std::cout << x << ' ';
    }
    std::cout << '\n';
}

Output:

3 1 4 1 5

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
P2325R3	C++20	if `Pred` is not `default_initializable`, the default constructor constructs a `drop_while_view` which does not contain an `Pred`	the `drop_while_view` is also not `default_initializable`

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