builder.h

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#pragma once

#include "bases.h"


namespace cauldron {
template<class Object, class ...Value>
class Builder : public CloneHelper<Object, Builder<Object, Value...>> {
 public:
  explicit Builder(const cauldron::Strategy<Value> &... strategy) :
      strategies_(std::make_tuple(strategy.clone()...)) {}

  Builder(const Builder<Object, Value...> &builder) :
      strategies_(builder.clone_strategies()) {}

  Object operator()() const override {
    auto strategies_count = std::tuple_size<decltype(strategies_)>{};
    return produce(strategies_,
                   std::make_index_sequence<strategies_count>{});
  }

 private:
  std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...> strategies_;

  template<std::size_t... Indices>
  Object produce(
      const std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...> &strategies,
      std::index_sequence<Indices...>
  ) const {
    return produce(std::get<Indices>(strategies)...);
  }

  Object produce(
      const std::unique_ptr<cauldron::Strategy<Value>> &... strategy
  ) const {
    return Object((*strategy)()...);
  }

  std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...>
  clone_strategies() const {
    auto strategies_count = std::tuple_size<decltype(strategies_)>{};
    return clone_strategies(strategies_,
                            std::make_index_sequence<strategies_count>{});
  }

  template<std::size_t... Indices>
  std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...>
  clone_strategies(
      const std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...> &strategies,
      std::index_sequence<Indices...>
  ) const {
    return clone_strategies(std::get<Indices>(strategies)...);
  }

  std::tuple<std::unique_ptr<cauldron::Strategy<Value>>...>
  clone_strategies(
      const std::unique_ptr<cauldron::Strategy<Value>> &... strategy
  ) const {
    return std::make_tuple(strategy->clone()...);
  }
};
}