[C++知识库]C++ std::tuple std::tie

#include <tuple>
#include <string>
#include <iostream>

using namespace std;

tuple<int, string, double> f()
{
    int i { 108};
    string s { "some text"};
    double d {.01};
    return { i, s, d};
}

int main()
{
    auto t = f();
    cout << get<0>(t) << " " << get<1>(t) << " " << get<2>(t) << endl;

    int myval;
    string myname;
    double mydecimal;
    tie(myval, myname, mydecimal) = f();
    cout << myval << " " << myname << " " << mydecimal << endl;

    return 0;
}

#include <iostream>     // std::cout
#include <tuple>        // std::tuple, std::get, std::tie, std::ignore

int main ()
{
  std::tuple<int,char> foo (10,'x'); // 构造tuple
  auto bar = std::make_tuple ("test", 3.1, 14, 'y');
  std::get<2>(bar) = 100;   //通过下标获取元素
  int myint; char mychar;
  std::tie (myint, mychar) = foo;  // unpack elements
  std::tie (std::ignore, std::ignore, myint, mychar) = bar;  // unpack (with ignore)
  mychar = std::get<3>(bar);
  std::get<0>(foo) = std::get<2>(bar); //通过下标获取元素
  std::get<1>(foo) = mychar;
  std::cout << "foo contains: ";
  std::cout << std::get<0>(foo) << ' ';
  std::cout << std::get<1>(foo) << '\n';

  return 0;
}