std::mdspan<T,Extents,LayoutPolicy,AccessorPolicy>:: mdspan
|
constexpr
mdspan
(
)
;
|
(1) | (since C++23) |
|
template
<
class
...
OtherIndexTypes
>
constexpr explicit mdspan ( data_handle_type p, OtherIndexTypes... exts ) ; |
(2) | (since C++23) |
|
template
<
class
OtherIndexType,
std::
size_t
N
>
constexpr
explicit
(
N
!
=
rank_dynamic
(
)
)
|
(3) | (since C++23) |
|
template
<
class
OtherIndexType,
std::
size_t
N
>
constexpr
explicit
(
N
!
=
rank_dynamic
(
)
)
|
(4) | (since C++23) |
|
constexpr
mdspan
(
data_handle_type p,
const
extents_type
&
ext
)
;
|
(5) | (since C++23) |
|
constexpr
mdspan
(
data_handle_type p,
const
mapping_type
&
m
)
;
|
(6) | (since C++23) |
|
constexpr
mdspan
(
data_handle_type p,
const
mapping_type
&
m,
const accessor_type & a ) ; |
(7) | (since C++23) |
|
template
<
class
OtherElementType,
class
OtherExtents,
class
OtherLayoutPolicy,
class
OtherAccessor
>
|
(8) | (since C++23) |
|
constexpr
mdspan
(
const
mdspan
&
rhs
)
=
default
;
|
(9) | (since C++23) |
|
constexpr
mdspan
(
mdspan
&&
rhs
)
=
default
;
|
(10) | (since C++23) |
Constructs an
mdspan
, optionally using user-supplied data handle
p
, layout mapping
m
, and accessor
a
. If extents
exts
or
ext
are supplied, they are converted to
extents_type
and used to initialize the layout mapping.
Contents |
Parameters
| p | - | a handle to the underlying data |
| m | - | a layout mapping |
| a | - | an accessor |
| ext | - |
a
std::extents
object
|
| exts | - | represents a multi-dimensional extents |
| other | - | another mdspan to convert from |
| rhs | - | another mdspan to copy or move from |
Effects
For the data members listed in the table below:
- If the corresponding initializer is empty, the data member is value-initialized .
- If the corresponding intiializer is not empty, the data member is direct-non-list-initialized with that initializer.
| Overload | Initializer for... | ||
|---|---|---|---|
ptr_
|
map_
|
acc_
|
|
| ( 1 ) | (empty) | ||
| ( 2 ) | std :: move ( p ) |
extents_type
( static_cast < index_type > ( std :: move ( exts ) ) ... ) |
(empty) |
| ( 3 ) | extents_type ( exts ) | ||
| ( 4 ) | |||
| ( 5 ) | ext | ||
| ( 6 ) | m | ||
| ( 7 ) | a | ||
| ( 8 ) |
other.
ptr_
|
other.
map_
|
other.
acc_
|
Constraints and supplement information
- rank_dynamic ( ) > 0
- std:: is_default_constructible_v < data_handle_type >
- std:: is_default_constructible_v < mapping_type >
- std:: is_default_constructible_v < accessor_type >
[
0
,
map_
.
required_span_size
(
)
)
is not an
accessible range
of
ptr_
and
acc_
for the values of
map_
and
acc_
after the invocation of this constructor, the behavior is undefined.
- ( std:: is_convertible_v < OtherIndexTypes, index_type > && ... )
- ( std:: is_nothrow_constructible < index_type, OtherIndexTypes > && ... )
- sizeof... ( OtherIndexTypes ) == rank ( ) || sizeof... ( OtherIndexTypes ) == rank_dynamic ( )
- std:: is_constructible_v < mapping_type, extents_type >
- std:: is_default_constructible_v < accessor_type >
[
0
,
map_
.
required_span_size
(
)
)
is not an accessible range of
p
and
acc_
for the values of
map_
and
acc_
after the invocation of these constructors, the behavior is undefined.
- std:: is_convertible_v < const OtherIndexType & , index_type >
- std:: is_nothrow_constructible_v < index_type, const OtherIndexType & >
- N == rank ( ) || N == rank_dynamic ( )
- std:: is_constructible_v < mapping_type, extents_type >
- std:: is_default_constructible_v < accessor_type >
[
0
,
map_
.
required_span_size
(
)
)
is not an accessible range of
p
and
acc_
for the values of
map_
and
acc_
after the invocation of these constructors, the behavior is undefined.
- std:: is_constructible_v < mapping_type, const extents_type & >
- std:: is_default_constructible_v < accessor_type >
[
0
,
map_
.
required_span_size
(
)
)
is not an accessible range of
p
and
acc_
for the values of
map_
and
acc_
after the invocation of these constructors, the behavior is undefined.
[
0
,
m.
required_span_size
(
)
)
is an accessible range of
p
and
acc_
for the value of
acc_
after the invocation of this constructor, the behavior is undefined.
[
0
,
m.
required_span_size
(
)
)
is not an accessible range of
p
and
a
, the behavior is undefined.
mapping_type >
|| ! std:: is_convertible_v < const OtherAccessor & , accessor_type > .
-
std::
is_constructible_v
< mapping_type, const OtherLayoutPolicy :: template mapping < OtherExtents > & > - std:: is_default_constructible_v < accessor_type >
- std:: is_constructible_v < data_handle_type, const OtherAccessor :: data_handle_type & >
- std:: is_constructible_v < extents_type, OtherExtents >
[
0
,
map_
.
required_span_size
(
)
)
is not an accessible range of
ptr_
and
acc_
for the values of
ptr_
,
map_
and
acc_
after the invocation of this constructor, the behavior is undefined.
|
If
static_extent
(
r
)
==
std::
dynamic_extent
|
(until C++26) |
|
If
static_extent
(
r
)
==
std::
dynamic_extent
|
(since C++26) |
Example
|
This section is incomplete
Reason: no example |
References
- C++23 standard (ISO/IEC 14882:2024):
-
- 24.7.3.6.2 Constructors [mdspan.mdspan.cons]
See also
| This section is incomplete |