std::ranges::drop_while_view<V,Pred>:: drop_while_view
From cppreference.net
<
cpp
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ranges
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drop while view
C++
Ranges library
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std::ranges::drop_while_view
| Member functions | ||||
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drop_while_view::drop_while_view
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| Deduction guides |
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drop_while_view
(
)
requires
std::
default_initializable
<
V
>
&&
std:: default_initializable < Pred > = default ; |
(1) | (since C++20) |
|
constexpr
explicit
drop_while_view
(
V base, Pred pred
)
;
|
(2) | (since C++20) |
Constructs a
drop_while_view
.
2)
Move constructs the underlying view
base_
from
base
and the predicate
pred_
from
pred
.
Parameters
| base | - | underlying view |
| pred | - | predicate |
Example
Run this code
#include <functional> #include <iostream> #include <ranges> int main() { static constexpr auto a = {-2, -7, -1, -8, -2, +-+8, 3, 1, 4, 1, 5}; auto positive = [](int x) { return 0 < x; }; for (auto v = std::ranges::drop_while_view{a, std::not_fn(positive)}; int x : v) 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 |
|---|---|---|---|
|
LWG 3714
( P2711R1 ) |
C++20 | the multi-parameter constructor was not explicit | made explicit |
| 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
|