// vim: set sts=8 ts=2 sw=2 tw=99 et:
//
// Copyright (C) 2013, David Anderson and AlliedModders LLC
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#ifndef _include_amtl_hashset_h_
#define _include_amtl_hashset_h_

#include <am-hashtable.h>

namespace ke {

// Template parameters:
//
// K - Key type.
// HashPolicy - A struct with a hash and comparator function for each lookup type:
//    static uint32_t hash(const Type &value);
//    static bool matches(const Type &value, const K &key);
//
// Like HashMap and HashTable, init() must be called to construct the set.
template <typename K,
          typename HashPolicy,
          typename AllocPolicy = SystemAllocatorPolicy>
class HashSet : public AllocPolicy
{
  struct Policy {
    typedef K Payload;

    template <typename Lookup>
    static uint32_t hash(const Lookup &key) {
      return HashPolicy::hash(key);
    }

    template <typename Lookup>
    static bool matches(const Lookup &key, const Payload &payload) {
      return HashPolicy::matches(key, payload);
    }
  };

  typedef HashTable<Policy, AllocPolicy> Internal;

 public:
  HashSet(AllocPolicy ap = AllocPolicy())
    : table_(ap)
  {
  }

  // capacity must be a power of two.
  bool init(size_t capacity = 16) {
    return table_.init(capacity);
  }

  typedef typename Internal::Result Result;
  typedef typename Internal::Insert Insert;
  typedef typename Internal::iterator iterator;

  template <typename Lookup>
  Result find(const Lookup &key) {
    return table_.find(key);
  }

  template <typename Lookup>
  Insert findForAdd(const Lookup &key) {
    return table_.findForAdd(key);
  }

  template <typename Lookup>
  void removeIfExists(const Lookup &key) {
    return table_.remove(key);
  }

  void remove(Result &r) {
    table_.remove(r);
  }

  // The map must not have been mutated in between findForAdd() and add().
  // The Insert object is still valid after add() returns, however.
  template <typename UK>
  bool add(Insert &i, UK &&key) {
    return table_.add(i, ke::Forward<UK>(key));
  }

  // This can be used to avoid compiler constructed temporaries, since AMTL
  // does not yet support move semantics. If you use this, the key and value
  // must be set after.
  bool add(Insert &i) {
    return table_.add(i);
  }

  iterator iter() {
    return iterator(&table_);
  }
  void clear() {
    table_.clear();
  }

  size_t estimateMemoryUse() const {
    return table_.estimateMemoryUse();
  }

 private:
  Internal table_;
};

}

#endif // _include_amtl_hashset_h_