std::mdspan<T,Extents,LayoutPolicy,AccessorPolicy>:: operator[]
From cppreference.com
|
template
<
class
...
OtherIndexTypes
>
constexpr reference operator [ ] ( OtherIndexTypes... indices ) const ; |
(1) | (since C++23) |
|
template
<
class
OtherIndexType
>
constexpr
reference operator
[
]
|
(2) | (since C++23) |
|
template
<
class
OtherIndexType
>
constexpr
reference operator
[
]
|
(3) | (since C++23) |
Returns a reference to the indices th element of the mdspan.
1)
Equivalent to
return
acc_.
access
(
ptr_, map_
(
static_cast
<
index_type
>
(
std
::
move
(
indices
)
)
...
)
)
;
.
This overload participates in overload resolution only if:
- ( std:: is_convertible_v < OtherIndexTypes, index_type > && ... ) is true ,
- ( std:: is_nothrow_constructible_v < index_type, OtherIndexTypes > && ... ) is true , and
- sizeof... ( OtherIndexTypes ) == rank ( ) is true .
Let
I
be
extents_type::
index-cast
(
std
::
move
(
indices
)
)
. Then the behavior is undefined if
I
is not a multidimensional index in
extents
(
)
, i.e.,
map_
(
I
)
<
map_.
required_span_size
(
)
is
false
.
2,3)
Let
P
be a parameter pack such that
std::
is_same_v
<
make_index_sequence
<
rank
(
)
>
, index_sequence
<
P...
>>
is
true
, then the operator is equivalent to
return
operator
[
]
(
extents_type
::
index-cast
(
std::
as_const
(
indices
[
P
]
)
)
...
)
;
.
This overload participates in overload resolution only if:
- std:: is_convertible_v < const OtherIndexType & , index_type > is true , and
- std:: is_nothrow_constructible_v < index_type, const OtherIndexType & > is true .
Parameters
| indices | - | the indices of the element to access |
Return value
A reference to the element.
Example
|
This section is incomplete
Reason: no example |
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 3974 | C++23 |
overloads
(2,3)
did not apply
extents_type::
index-cast
|
applies |
See also
| This section is incomplete |