(Optional) C++ - Lambda Expressions

Introduction

Anything more beginner-friendly?

Recursive Lambdas

If we add the following from the link above in C++14:

namespace std {

template<class Fun>
class y_combinator_result {
  Fun fun_;
public:
  template<class T>
  explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

  template<class ...Args>

Then we can have code like the following!

int main() {
  cout << y_combinator([](auto gcd, int a, int b) -> int {
    return b == 0 ? a : gcd(b, a % b);
  })(20,30) << "\n"; // outputs 10
}

Looks like ecnerwala uses these a lot.