diff options
| -rw-r--r-- | c++.html.markdown | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/c++.html.markdown b/c++.html.markdown index 44cad665..1065b9e8 100644 --- a/c++.html.markdown +++ b/c++.html.markdown @@ -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' + ``` Further Reading: |