[C++] structured binding declaration

개요

• rvalue의 하위 요소를 바인딩

예제

• 코드

   #include <iostream>
   #include <string>
   #include <tuple>
      
   using namespace std;
      
   void test1() {
   	int i[2] = {1, 3};
      
   	auto [x1, y1] = i;
   	cout << x1 << ", " << y1 << endl;
   	++x1;
   	cout << i[0] << ", " << i[1] << endl;
      
   	cout << endl;
      
   	auto &[x2, y2] = i;
   	cout << x1 << ", " << y1 << endl;
   	++x2;
   	cout << i[0] << ", " << i[1] << endl;
   }
      
   void test2() {
   	tuple<int, string> t = make_tuple(1, "a");
      
   	cout << get<0>(t) << ", " << get<1>(t) << endl;
   	++get<0>(t);
   	cout << get<0>(t) << ", " << get<1>(t) << endl;
      
   	cout << endl;
      
   	auto [i1, s1] = t;
   	cout << i1 << ", " << s1 << endl;
   	++i1;
   	cout << get<0>(t) << ", " << get<1>(t) << endl;
      
   	cout << endl;
      
   	auto &[i2, s2] = t;
   	cout << i2 << ", " << s2 << endl;
   	++i2;
   	cout << get<0>(t) << ", " << get<1>(t) << endl;
   }
      
   void test3() {
   	struct S {
   			int i;
   			string s;
   	};
      
   	auto [i, s] = S{1, "a"};
   	cout << i << ", " << s << endl;
   }
      
   int main() {
   	test1();
      
   	cout << "------" << endl;
      
   	test2();
      
   	cout << "------" << endl;
      
   	test3();
      
   	return 0;
   }
  

• 실행 결과

   1, 3
   1, 3
      
   2, 3
   2, 3
   ------
   1, a
   2, a
      
   2, a
   2, a
      
   2, a
   3, a
   ------
   1, a