std::ranges::view_interface<D>:: data
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Range primitives | |||||||
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Range concepts | |||||||||||||||||||
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Range factories | |||||||||
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Range adaptors | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Helper items | |||||||||||||||||
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Member functions | ||||
(C++23)
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(C++23)
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data
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constexpr
auto
data
(
)
requires std:: contiguous_iterator < ranges:: iterator_t < D >> ; |
(1) | (since C++20) |
constexpr
auto
data
(
)
const
requires
ranges::
range
<
const
D
>
&&
|
(2) | (since C++20) |
The default implementation of
data()
member function obtains the address denoted by the beginning iterator via
std::to_address
, which is also the lowest address of the contiguous storage (implied by
contiguous_iterator
) referenced by the view of the derived type when the view is not empty.
derived
be
static_cast
<
D
&
>
(
*
this
)
. Equivalent to
return
std::
to_address
(
ranges::
begin
(
derived
)
)
;
.
derived
is
static_cast
<
const
D
&
>
(
*
this
)
.
Parameters
(none)
Return value
The address denoted by the beginning iterator.
Notes
Following derived types may use the default implementation of
data()
:
- std::ranges::common_view
- std::ranges::drop_view
- std::ranges::drop_while_view
- std::ranges::ref_view
- std::ranges::subrange
- std::ranges::take_view
- std::ranges::take_while_view
Following types are derived from
std::ranges::view_interface
and do not declare their own
data()
member function, but they cannot use the default implementation, because their iterator types never satisfy
contiguous_iterator
:
- std::ranges::basic_istream_view
- std::ranges::elements_view
- std::ranges::filter_view
- std::ranges::iota_view
- std::ranges::join_view
- std::ranges::lazy_split_view
- std::ranges::reverse_view
- std::ranges::split_view
- std::ranges::transform_view
Example
#include <array> #include <iostream> #include <ranges> #include <string_view> int main() { constexpr std::string_view str { "Hello, C++20!" }; std::cout << (str | std::views::drop(7)).data() << '\n'; constexpr static std::array a { 1,2,3,4,5 }; constexpr auto v { a | std::views::take(3) }; static_assert( &a[0] == v.data() ); }
Output:
C++20!
See also
(C++17)
|
obtains the pointer to the underlying array
(function template) |
(C++20)
|
obtains a pointer to the beginning of a contiguous range
(customization point object) |
(C++20)
|
obtains a pointer to the beginning of a read-only contiguous range
(customization point object) |
(C++20)
|
obtains a raw pointer from a pointer-like type
(function template) |