// Ex10_16.cpp Wrapping a lambda expression
#include <iostream>
#include <functional>

// Global wrapper for lambda expression computing HCF
std::function<long long(long long, long long)> hcf =
[&](long long m, long long n) mutable ->long long{
  if (m < n) return hcf(n, m);
  long long remainder{ m%n };
  if (0 == remainder) return n;
  return hcf(n, remainder); };
int main()
{
  // A lambda expression assigned to a function pointer
  // that outputs the highest common factor of the arguments
  auto showHCF = [](long long a, long long b) {
    std::cout << "For numbers " << a << " and " << b
              << " the highest common factor is " << hcf(a, b) << std::endl;
  };
  long long a{ 17719LL }, b{ 18879LL };
  showHCF(a, b);
  showHCF(103LL * 53 * 17 * 97, 3LL * 29 * 103);
  showHCF(53LL * 941 * 557 * 43 * 29 * 229, 83LL * 89 * 941 * 11 * 17 * 863 * 431);
}