// Copyright 2012-2022 The ANTLR Project
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#pragma once

#include <unordered_set>

#include "atn/PredictionContext.h"

namespace antlr4 {
namespace atn {

  class ANTLR4CPP_PUBLIC PredictionContextCache final {
  public:
    PredictionContextCache() = default;

    PredictionContextCache(const PredictionContextCache&) = delete;
    PredictionContextCache(PredictionContextCache&&) = delete;

    PredictionContextCache& operator=(const PredictionContextCache&) = delete;
    PredictionContextCache& operator=(PredictionContextCache&&) = delete;

    void put(const Ref<const PredictionContext> &value);

    Ref<const PredictionContext> get(const Ref<const PredictionContext> &value) const;

  private:
    struct ANTLR4CPP_PUBLIC PredictionContextHasher final {
      size_t operator()(const Ref<const PredictionContext> &predictionContext) const;
    };

    struct ANTLR4CPP_PUBLIC PredictionContextComparer final {
      bool operator()(const Ref<const PredictionContext> &lhs,
                      const Ref<const PredictionContext> &rhs) const;
    };

    std::unordered_set<Ref<const PredictionContext>,
                       PredictionContextHasher, PredictionContextComparer> _data;
  };

}  // namespace atn
}  // namespace antlr4