Difference between revisions of "cpp/container/array/tuple size"
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| − | {{cpp/title|tuple_size{{ | + | {{cpp/title|tuple_size{{petty|<std::array>}}}} |
{{cpp/container/array/navbar}} | {{cpp/container/array/navbar}} | ||
| − | {{ | + | {{ddcl|header=array|since=c++11| |
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template< class T, std::size_t N > | template< class T, std::size_t N > | ||
struct tuple_size< std::array<T, N> > : | struct tuple_size< std::array<T, N> > : | ||
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{ }; | { }; | ||
}} | }} | ||
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Provides access to the number of elements in an {{lc|std::array}} as a compile-time constant expression. | Provides access to the number of elements in an {{lc|std::array}} as a compile-time constant expression. | ||
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{{ddcl|since=c++17|1= | {{ddcl|since=c++17|1= | ||
template< class T > | template< class T > | ||
| − | + | constexpr std::size_t tuple_size_v = tuple_size<T>::value; | |
}} | }} | ||
Latest revision as of 08:38, 24 September 2024
| Defined in header <array>
|
||
| template< class T, std::size_t N > struct tuple_size< std::array<T, N> > : |
(since C++11) | |
Provides access to the number of elements in an std::array as a compile-time constant expression.
Contents |
[edit] Helper variable template
| template< class T > constexpr std::size_t tuple_size_v = tuple_size<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
N, the number of elements in the array (public static member constant) |
Member functions
| operator std::size_t |
converts the object to std::size_t, returns value (public member function) |
| operator() (C++14) |
returns value (public member function) |
Member types
| Type | Definition |
value_type
|
std::size_t |
type
|
std::integral_constant<std::size_t, value> |
[edit] Example
Run this code
#include <array> int main() { auto arr = std::to_array("ABBA"); static_assert(std::tuple_size<decltype(arr)>{} == 5); }
[edit] See also
| Structured binding (C++17) | binds the specified names to sub-objects or tuple elements of the initializer |
| (C++11) |
obtains the number of elements of a tuple-like type (class template) |
| (C++11) |
obtains the size of
a |
| (C++11) |
obtains the size of a pair (class template specialization) |
| obtains the size of a std::ranges::subrange (class template specialization) |
