/*
File: lambda1.cpp

Simple example of a lambda expression in C++

Lambda expressions that do not capture any variables
can be type cast to function pointers.
*/

#include <iostream>
using namespace std ;

typedef int (* f_type) (int) ;

void apply( f_type f, int A[], int n) {
   for (int i=0 ; i < n ; i++) {
      A[i] = f( A[i] ) ;
   }
}


int main () {

   auto add3 = [](int n) { return n + 3 ; } ;  // a lambda expression in C++

   cout << "add3(5) = " << add3(5) << endl ;


   int B[10] = { 10, 11, 12, 13, 14, 15, 16, 17, 18, 19} ;

   printf("Before:\n") ;
   for (int i=0 ; i < 10 ; i++) {
      cout << "   B[" << i << "] = " << B[i] << endl ;
   }

   apply (add3, B, 10) ;

   printf("\n\nAfter calling apply(add3, B, 10):\n") ;
   for (int i=0 ; i < 10 ; i++) {
      cout << "   B[" << i << "] = " << B[i] << endl ;
   }

   apply ( [](int n){ return n + 5 ;}, B, 10) ;  // real intention

   printf("\n\nAfter calling apply(..., B, 10):\n") ;
   for (int i=0 ; i < 10 ; i++) {
      cout << "   B[" << i << "] = " << B[i] << endl ;
   }
}