Merge pull request #2119 from Jaskamalkainth/master

[C++ / en] Added Tuple.
This commit is contained in:
ven 2016-01-28 14:01:02 +01:00
commit 8792c10cc6

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@ -955,6 +955,52 @@ 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;
const 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'
```
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