#include <functional>
#include <cstdio>

template <typename R, typename V1, typename V2>
std::function<R(V2)> pa(const std::function<R(V1,V2)> &f, V1 v) {
    return [&](V2 x) { return f(v, x); };
}

template <typename R, typename V1, typename V2>
std::function<std::function<R(V1)>(V2)> curry(const std::function<R(V1,V2)> &f) {
    return [&](V2 x) { return pa(f, x); };
}

template <typename Lhs, typename Rhs>
auto times(const Lhs &lhs, const Rhs &rhs) -> decltype(lhs * rhs) {
	return lhs * rhs;
}

int main() {
	std::function<int(int, int)> itimes = times<int, int>;
	
	printf("pa: %d\n", pa(itimes, 10)(20));
	printf("curry: %d\n", curry(itimes)(10)(20));
}