tuple_size Class <array>
The latest version of this topic can be found at Visual Studio 2017 Documentation.
Wraps the size of an array.
Syntax
template <class Tuple>
struct tuple_size;
// struct to determine number of elements in array
template <class T, size_t Size>
struct tuple_size<array<T, Size>>
: integral_constant<size_t, Size>;
// size of const tuple
template <class Tuple>
struct tuple_size<const Tuple>;
// size of volatile tuple
template <class Tuple>
struct tuple_size<volatile Tuple>;
// size of const volatile tuple
template <class Tuple>
struct tuple_size<const volatile Tuple>;
Template Parameters
T
The type of an element.
Size
The size of the array.
Remarks
This template is a specialization of the template class tuple_size Class. It has a member value that is an integral constant expression whose value is N, which is the size of the array.
Example
#include <array>
#include <iostream>
using namespace std;
typedef array<int, 4> MyArray;
int main()
{
MyArray c0 { 0, 1, 2, 3 };
// display contents " 0 1 2 3"
for (const auto& e : c0)
{
cout << e;
}
cout << endl;
// display size " 4"
cout << " " << tuple_size<MyArray>::value << endl;
}
/*
Output:
0123
4
*/
Requirements
Header: <array>
Namespace: std