| Defined in header <array> | ||
|---|---|---|
template< class T, size_t N >
class tuple_size< array<T, N> > :
public integral_constant<size_t, N>
{ }; | (1) | (since C++11) |
Provides access to the number of elements in an std::array as a compile-time constant expression.
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> |
Example
#include <iostream>
#include <array>
template<class T>
void test(T t)
{
int a[std::tuple_size<T>::value]; // can be used at compile time
std::cout << std::tuple_size<T>::value << '\n';
}
int main()
{
std::array<float, 3> arr;
test(arr);
}Output:
3
See also
obtains the size of tuple at compile time (class template specialization) |
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