std:: get (std::array)
|
Defined in header
<array>
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||
|
template
<
std::
size_t
I,
class
T,
std::
size_t
N
>
T & get ( std:: array < T,N > & a ) noexcept ; |
(1) |
(since C++11)
(constexpr since C++14) |
|
template
<
std::
size_t
I,
class
T,
std::
size_t
N
>
T && get ( std:: array < T,N > && a ) noexcept ; |
(2) |
(since C++11)
(constexpr since C++14) |
|
template
<
std::
size_t
I,
class
T,
std::
size_t
N
>
const T & get ( const std:: array < T,N > & a ) noexcept ; |
(3) |
(since C++11)
(constexpr since C++14) |
|
template
<
std::
size_t
I,
class
T,
std::
size_t
N
>
const T && get ( const std:: array < T,N > && a ) noexcept ; |
(4) |
(since C++11)
(constexpr since C++14) |
Extracts the
I
th
element from the array using
tuple-like
interface.
I
must be an integer value in range
[
0
,
N
)
. This is enforced at compile time as opposed to
at()
or
operator[]
.
Parameters
| a | - | array whose contents to extract |
Return value
A reference to the
I
th
element of
a
.
Complexity
Constant.
Example
#include <array> #include <iostream> constexpr std::array v{1, 2, 3}; static_assert(get<0>(v) == 1 && get<1>(v) == 2 && get<2>(v) == 3); int main() { std::array<int, 3> a; // set values: get<0>(a) = 1, get<1>(a) = 2, get<2>(a) = 3; // get values: std::cout << '(' << get<0>(a) << ',' << get<1>(a) << ',' << get<2>(a) << ")\n"; }
Output:
(1,2,3)
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 2485 | C++11 | there are no overloads for const array&& | the overloads are added |
See also
| Structured binding (C++17) | binds the specified names to sub-objects or tuple elements of the initializer |
|
access specified element
(public member function) |
|
|
access specified element with bounds checking
(public member function) |
|
|
(C++11)
|
tuple accesses specified element
(function template) |
|
(C++11)
|
accesses an element of a
pair
(function template) |
|
(C++17)
|
reads the value of the variant given the index or the type (if the type is unique), throws on error
(function template) |
|
(C++20)
|
obtains iterator or sentinel from a
std::ranges::subrange
(function template) |
|
(C++26)
|
obtains a reference to real or imaginary part from a
std::complex
(function template) |