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

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Ranges library

Range access
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
Range conversions
to (C++23)
Range primitives
range_size_trange_difference_trange_value_trange_reference_t	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)	elements_of (C++23)
Dangling iterator handling
dangling	borrowed_iterator_t	borrowed_subrange_t
Range concepts
range borrowed_range sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
Views
view_interface	subrange
Range factories
empty_viewviews::empty single_viewviews::single	iota_viewviews::iota repeat_viewviews::repeat (C++23)(C++23)	basic_istream_viewviews::istream
Range adaptors
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (C++23)(C++23) filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (C++23)(C++23) lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)
Range generators
std::generator (C++23)
Range adaptor objects
Range adaptor closure objects
range_adaptor_closure (C++23)
Helper items
copyable-box movable-box (until C++23)(C++23)	simple-view non-propagating-cache

 

std::ranges::drop_while_view

Member functions

drop_while_view::drop_while_view (C++20)

drop_while_view::base (C++20)

drop_while_view::pred (C++20)

drop_while_view::begin (C++20)

drop_while_view::end (C++20)

Deduction guides

 

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.

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

Run this code

#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
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