Added Tuple

c++.html.markdown

@@ -955,6 +955,54 @@ v.push_back(Foo());  // New value is copied into the first Foo we inserted
 // explanation of why this works.
 v.swap(vector<Foo>());
 
+
+///////////////////////////////////////
+// Tuples (C++11 and above)
+///////////////////////////////////////
+
+#include<tuple>
+
+// Conceptually, Tuples are similar to  old data structures (C-like structs) but instead of having named data members , 
+// its elements are accessed by their order in the tuple.
+
+// We start with constructing a tuple.
+//
+// Packing values into tuple
+auto first  = make_tuple ( 10 , 'A' ) ;
+const int maxN = 1e9;
+int maxL = 15;
+auto second = make_tuple ( maxN , maxL ) ;
+
+// printing elements of 'first' tuple
+cout << get<0>(first) << " " << get<1>(first) << "\n"; //prints : 10 A
+
+// printing elements of 'second' tuple
+cout << get<0>(second)<< " " << get<1>(second) << "\n"; // prints: 1000000000 15
+
+
+// Unpacking tuple into variables
+
+int first_int;
+char first_char;
+tie (first_int , first_char ) = first;
+cout << first_int << " " << first_char << "\n";  // prints : 10 A
+
+// We can also create tuple like this.
+
+tuple<int , char , double> third ( 11 ,'A' , 3.14141);
+// tuple_size returns number of elements in a tuple (as a constexpr)
+
+cout << tuple_size< decltype(third)>::value << "\n"; // prints: 3
+
+// tuple_cat concatenates the elements of all the tuples in the same order.
+
+auto concatenated_tuple = tuple_cat( first, second ,third);
+// concatenated_tuple becomes = (10 , 'A' , 1e9 , 15 , 11 , 'A' , 3.14141 ) 
+
+cout << get<0>(concatenated_tuple) << "\n"; // prints: 10
+cout << get<3>(concatenated_tuple) << "\n"; // prints: 15
+cout << get<5>(concatenated_tuple) << "\n"; // prints: 'A'
+
 ```
 Further Reading: