tuple_element Class <tuple>
Bindet den Typ eines Elements tuple ein.
template<int Idx, class Tuple>
class tuple_element {
typedef Ti type;
};
Parameter
Idx
Der Index des Elements festzulegen.Tuple
Der Typ des Tupels.
Hinweise
Die Vorlagenklasse hat geschachteltes Typedef type, die ein Synonym für den Typ am Index Idx des Tupeltyps Tuple ist.
Beispiel
// std_tr1__tuple__tuple_element.cpp
// compile with: /EHsc
#include <tuple>
#include <iostream>
#include <utility>
typedef std::tuple<int, double, int, double> Mytuple;
int main()
{
Mytuple c0(0, 1, 2, 3);
// display contents " 0 1 2 3"
std::cout << " " << std::get<0>(c0);
std::cout << " " << std::get<1>(c0);
std::cout << " " << std::get<2>(c0);
std::cout << " " << std::get<3>(c0);
std::cout << std::endl;
// display first element " 0"
std::tuple_element<0, Mytuple>::type val = std::get<0>(c0);
std::cout << " " << val;
std::cout << std::endl;
return (0);
}
Anforderungen
Header: <tuple>
Namespace: std