cpp-cli/include/cli/lambda_cast.h

//
//  lambda_cast.h
//  tax-calculator
//
//  Created by Sam Jaffe on 10/8/20.
//
//  Credit given to Nikos Athanasiou for this solution to the
//  problem of getting the argument types of a lambda.
//  https://stackoverflow.com/questions/13358672/
//

#pragma once

#include <functional>

namespace lambdas {
template <typename T> struct memfun_type { using type = void; };

template <typename Ret, typename Class, typename... Args>
struct memfun_type<Ret (Class::*)(Args...) const> {
  using type = std::function<Ret(Args...)>;
};

template <typename F>
typename memfun_type<decltype(&F::operator())>::type FFL(F const & func) {
  return func;
}
}