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  1. #include <iostream>
  2. #include <functional>
  3. using namespace std;
  4.  
  5.         class Inner
  6.         {
  7.             int myx; 
  8.         public:
  9.             Inner(int x);    // this represents the capture of the lambda
  10.             int operator()(int k);  // this is the function of adding k to the catpture
  11.         };
  12.  
  13.         Inner::Inner(int x) 
  14.         {
  15.             myx = x; 
  16.         }
  17.         int Inner::operator()(int k)
  18.         {
  19.          	cout << "Class Inner arg:" <<k<<" with a capture of "<<myx<<endl; 
  20.             return myx + k;
  21.         }
  22.  
  23.         class Suma
  24.         {
  25.         public:
  26.             Inner operator()(int x);
  27.         };
  28.  
  29.         Inner Suma::operator()(int x) 
  30.         {
  31.        	     cout<<"Class Suma is the function "<<x<<"+ something"<<endl;
  32.              return Inner(x); 
  33.         };
  34.  
  35.  
  36. int main() {
  37.  
  38. 	auto lsuma = [](int x)->function<int(int)>   // lsuma is a local lambda
  39.     {
  40.     	cout<<"Suma lambda is the function "<<x<<"+ something"<<endl;
  41.         return [x](int y)
  42.         {
  43.         	cout << "inner lambda arg:" <<y<<" with a capture of "<<x<<endl; 
  44.             return x+y;
  45.         };
  46.     };
  47.  
  48.  
  49.     Suma f;                                  // f is also a local, but an object 
  50.     cout << lsuma(3)(2) <<endl; 
  51.     cout << f(3)(2)<<endl; 
  52.  
  53. 	return 0;
  54. }
Success #stdin #stdout 0s 3460KB
comments (?)
stdin 
Standard input is empty
stdout 
Suma lambda is the function 3+ something
inner lambda arg:2 with a capture of 3
5
Class Suma is the function 3+ something
Class Inner arg:2 with a capture of 3
5
https://ideone.com/pjTfkD
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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