From 32f18cd992b5b6988a3b37eaa533f8215d83fe2e Mon Sep 17 00:00:00 2001 From: Jaskamal Kainth Date: Thu, 28 Jan 2016 10:38:51 +0530 Subject: [PATCH] Added Tuple --- c++.html.markdown | 48 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/c++.html.markdown b/c++.html.markdown index 44cad665..b8ab656c 100644 --- a/c++.html.markdown +++ b/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()); + +/////////////////////////////////////// +// Tuples (C++11 and above) +/////////////////////////////////////// + +#include + +// 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 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: