concepts

[antialize]

gcc 6 just implemented concepts lite, perhaps we could extend tpie to use them for pipelining, here is an example of how they work.

#include <type_traits>
#include <utility>

class node {};

template <typename T>
concept bool pipenode() {
  return std::is_base_of<node, T>::value;
}

template <typename T>
concept bool movable() {
  return requires(T i, T x) {
    {x = std::move(i)}
    {new T(std::move(i))}
  };
}

template <typename T>
concept bool pushable_generic() {
  return requires (T t, typename T::item_type i) {
    {t.push(i)} -> void
                     };
}

template <typename T>
concept bool pushable_generic_node = pushable_generic<T>() && pipenode<T>() && movable<T>();

struct Monkey : public node{
  Monkey() {}
  //Monkey(Monkey && m) = delete;                                                                                                                                                                                                                                                        

  typedef int item_type;

  void push(int) {}
};

template <pushable_generic_node T>
void hat(T node) {
}

int main() {
  hat(Monkey());
}