fork download
copy 
  1. // bind example
  2. #include <iostream>     // std::cout
  3. #include <functional>   // std::bind
  4.  
  5. // a function: (also works with function object: std::divides<double> my_divide;)
  6. double my_divide (double x, double y) {return x/y;}
  7.  
  8. struct MyPair {
  9.   double a,b;
  10.   double multiply() {return a*b;}
  11. };
  12.  
  13. int main () {
  14.   using namespace std::placeholders;    // adds visibility of _1, _2, _3,...
  15.  
  16.   // binding functions:
  17.   auto fn_five = std::bind (my_divide,10,2);               // returns 10/2
  18.   std::cout << fn_five() << '\n';                          // 5
  19.  
  20.   auto fn_half = std::bind (my_divide,_1,2);               // returns x/2
  21.   std::cout << fn_half(10) << '\n';                        // 5
  22.  
  23.   auto fn_invert = std::bind (my_divide,_2,_1);            // returns y/x
  24.   std::cout << fn_invert(10,2) << '\n';                    // 0.2
  25.  
  26.   auto fn_rounding = std::bind<int> (my_divide,_1,_2);     // returns int(x/y)
  27.   std::cout << fn_rounding(10,3) << '\n';                  // 3
  28.  
  29.   MyPair ten_two {10,2};
  30.  
  31.   // binding members:
  32.   auto bound_member_fn = std::bind (&MyPair::multiply,_1); // returns x.multiply()
  33.   std::cout << bound_member_fn(ten_two) << '\n';           // 20
  34.  
  35.   auto bound_member_data = std::bind (&MyPair::a,ten_two); // returns ten_two.a
  36.   std::cout << bound_member_data() << '\n';                // 10
  37.  
  38.   return 0;
  39. }
Success #stdin #stdout 0s 15240KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
5
5
0.2
3
20
10
https://ideone.com/FFGxhq
language:
C++ (gcc 8.3)
created:
6 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!