A tuple is an object that can hold a number of elements. The elements can be different data types. The elements of tuples are initialized as arguments in the order in which they will be accessed.
The functions-
tuple_element() and tuple_size()
are only defined for elements using tuple_like interface.
tuple_element():
The C++ function tuple_element(array) provides compile-type indexed access to the type of the elements of the array using a tuple-like interface.
Syntax-
template< size_t I, class T, size_t N > struct tuple_element<I, array<T, N> >;
Parameters-
T − type for which the tuple element is obtained. I − index of the element. N − the size of the array.
Example-
Below is the C++ program to implement the concept of tuple_element(array)-
// C++ program to implement // the above approach #include <array> #include <iostream> #include <tuple> #include <type_traits> using namespace std;
// Driver code int main()
{ // Define array
array< int , 3> data{ 3, 5, 10 };
// Type of element at index 0
using type = std::tuple_element<0,
decltype (data)>::type;
// Compare type with int
// returns true
cout << std::is_same<type,
int >::value
<< '\n' ;
// Compare type with char
// returns false
cout << std::is_same<type,
char >::value
<< '\n' ;
} |
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tuple_size():
The C++ function tuple_size(array) returns the total number of elements present in the array.
Syntax-
template< class T, size_t N > class tuple_size< array<T, N> > : integral_constant<size_t, N> { };
Parameters-
T − type for which the tuple size is obtained.
Example-
Below is the C++ program to implement the concept of tuple_size()-
// C++ program to implement // the above approach #include <array> #include <iostream> using namespace std;
// Driver code int main()
{ // Array of size 6
array< int , 6> a;
// Find size using tuple_size
cout << tuple_size< decltype (a)>::value;
return 0;
} |
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