std::ranges::take_view<V>:: reserve_hint

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begin
cbegin
end
cend

rbegin
crbegin
rend
crend

size
ssize
data
cdata

reserve_hint (C++26)
empty

Range conversions
std::from_range_t std::from_range (C++23) (C++23)
to (C++23)

Dangling iterator handling
dangling
borrowed_iterator_t
borrowed_subrange_t

Range primitives

range_size_t range_difference_t range_value_t
elements_of (C++23)

iterator_t const_iterator_t sentinel_t const_sentinel_t

(C++23) (C++23)

range_reference_t range_const_reference_t range_rvalue_reference_t range_common_reference_t

(C++23)

Range concepts

range
borrowed_range
common_range

sized_range
viewable_range
view

input_range
output_range
forward_range

bidirectional_range
random_access_range
contiguous_range

approximately_sized_range (C++26)
constant_range (C++23)

Views

view_interface

subrange

Range factories

empty_view views::empty

single_view views::single

basic_istream_view views::istream

iota_view views::iota

repeat_view views::repeat

(C++23) (C++23)

Range adaptors

views::all_t views::all
as_rvalue_view views::as_rvalue (C++23) (C++23)
filter_view views::filter
transform_view views::transform
take_view views::take
take_while_view views::take_while
common_view views::common
views::counted
to_input_view views::to_input (C++26) (C++26)

ref_view
drop_view views::drop
drop_while_view views::drop_while
lazy_split_view views::lazy_split
split_view views::split
join_view views::join
join_with_view views::join_with (C++23) (C++23)
concat_view views::concat (C++26) (C++26)
cache_latest_view views::cache_latest (C++26) (C++26)

owning_view
reverse_view views::reverse
as_const_view views::as_const (C++23) (C++23)
elements_view views::elements
keys_view views::keys
values_view views::values
enumerate_view views::enumerate (C++23) (C++23)
zip_view views::zip (C++23) (C++23)
zip_transform_view views::zip_transform (C++23) (C++23)

adjacent_view views::adjacent (C++23) (C++23)
views::pairwise (C++23)
adjacent_transform_view views::adjacent_transform (C++23) (C++23)
views::pairwise_transform (C++23)
chunk_view views::chunk (C++23) (C++23)
slide_view views::slide (C++23) (C++23)
chunk_by_view views::chunk_by (C++23) (C++23)
stride_view views::stride (C++23) (C++23)
cartesian_product_view views::cartesian_product (C++23) (C++23)

Range generators
std::generator (C++23)

Range adaptor closure objects
range_adaptor_closure (C++23)

Range adaptor objects

Helper items

copyable-box
movable-box

(until C++23)

(C++23)

simple-view
non-propagating-cache

constexpr auto reserve_hint ( )	(1)	(自 C++26 起)
constexpr auto reserve_hint ( ) const	(2)	(自 C++26 起)

令 W 为用于重载 (1) 的 V 或用于重载 (2) 的 const V 。等价于

if constexpr ( ranges :: approximately_sized_range < W > )
{
auto n = static_cast < ranges:: range_difference_t < W >> ( ranges :: reserve_hint ( base_ ) ) ;
return to-unsigned-like ( ranges:: min ( n, count_ ) ) ;
}
return to-unsigned-like ( count_ ) ;

Compiler support
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Language
Standard library
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Diagnostics library
Memory management library
Metaprogramming library (C++11)
General utilities library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library (C++17)
Concurrency support library (C++11)
Execution control library (C++26)
Technical specifications
Symbols index
External libraries

Member functions
take_view::take_view
take_view::base
take_view::begin
take_view::end
take_view::size
take_view::reserve_hint (C++26)
Deduction guides
Sentinel
Member functions
take_view:: sentinel :: sentinel
Non-member functions
take_view:: sentinel ::base
operator== (std::counted_iterator,take_view:: sentinel )

cppreference.net

Namespaces

Variants

std::ranges::take_view<V>:: reserve_hint

目录

返回值

注释

示例

参阅