visitors.hpp

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/*
 * Title:        bits/visitors.hpp
 * Description:  C++ header-only wrapper for C-ABI data_t type
 * $Copyright (c) 2015-2016 Software AG, Darmstadt, Germany and/or Software AG USA Inc., Reston, VA, USA, and/or its subsidiaries and/or its affiliates and/or their licensors.$
 * Use, reproduction, transfer, publication or disclosure is prohibited except as specifically provided for in your License Agreement with Software AG
 * @Version:     $Id: visitors.hpp 294926 2016-11-09 18:33:24Z matj $
 */

#ifndef _DATAT_BITS_INCLUDE_TAG
#error Must only be included from sag_connectivity_cpp.hpp, use that instead
#endif


template<typename DERIVED, typename RV>
class visitor
{
public:
        typedef RV result_type;
        typedef DERIVED derived_t;

        result_type operator()() const { return derived().visitEmpty(); }
        result_type visitEmpty() const { return derived().error("empty"); }

        result_type operator()(int64_t &i) const { return derived().visitInteger(i); }
        result_type visitInteger(int64_t &i) const { return derived().error("integer"); }

        result_type operator()(double &i) const { return derived().visitDouble(i); }
        result_type visitDouble(double &i) const { return derived().error("double"); }

        result_type operator()(bool &i) const { return derived().visitBoolean(i); }
        result_type visitBoolean(bool &i) const { return derived().error("boolean"); }

        result_type operator()(const char *&i) const { return derived().visitString(i); }
        result_type visitString(const char *&i) const { return derived().error("string"); }

        result_type operator()(decimal_t &i) const { return derived().visitDecimal(i); }
        result_type visitDecimal(decimal_t &i) const { return derived().error("decimal"); }

        result_type operator()(buffer_t &i) const { return derived().visitBuffer(i); }
        result_type visitBuffer(buffer_t &i) const { return derived().error("buffer"); }

        result_type operator()(list_t &i) const { return derived().visitList(i); }
        result_type visitList(list_t &i) const { return derived().error("list"); }

        result_type operator()(map_t &i) const { return derived().visitMap(i); }
        result_type visitMap(map_t &i) const { return derived().error("map"); }

        result_type operator()(sag_underlying_custom_t &i) const { return derived().visitCustom(i); }
        result_type visitCustom(sag_underlying_custom_t &i) const { return derived().error("custom"); }

protected:
        result_type error(const std::string &reason) const { throw std::runtime_error("Visit type error: "+reason); }
private:
        const derived_t &derived() const { return static_cast<const derived_t&>(*this); }
};

template<typename DERIVED, typename RV>
class const_visitor
{
public:
        typedef RV result_type;
        typedef DERIVED derived_t;

        result_type operator()() const { return derived().visitEmpty(); }
        result_type visitEmpty() const { return derived().error("empty"); }

        result_type operator()(int64_t i) const { return derived().visitInteger(i); }
        result_type visitInteger(int64_t i) const { return derived().error("integer"); }

        result_type operator()(double i) const { return derived().visitDouble(i); }
        result_type visitDouble(double i) const { return derived().error("double"); }

        result_type operator()(bool i) const { return derived().visitBoolean(i); }
        result_type visitBoolean(bool i) const { return derived().error("boolean"); }

        result_type operator()(const char *i) const { return derived().visitString(i); }
        result_type visitString(const char *i) const { return derived().error("string"); }

        result_type operator()(const decimal_t &i) const { return derived().visitDecimal(i); }
        result_type visitDecimal(const decimal_t &i) const { return derived().error("decimal"); }

        result_type operator()(const buffer_t &i) const { return derived().visitBuffer(i); }
        result_type visitBuffer(const buffer_t &i) const { return derived().error("buffer"); }

        result_type operator()(const list_t &i) const { return derived().visitList(i); }
        result_type visitList(const list_t &i) const { return derived().error("list"); }

        result_type operator()(const map_t &i) const { return derived().visitMap(i); }
        result_type visitMap(const map_t &i) const { return derived().error("map"); }

        result_type operator()(const sag_underlying_custom_t &i) const { return derived().visitCustom(i); }
        result_type visitCustom(const sag_underlying_custom_t &i) const { return derived().error("custom"); }

protected:
        result_type error(const std::string &reason) const { throw std::runtime_error("Visit type error: "+reason); }
private:
        const derived_t &derived() const { return static_cast<const derived_t&>(*this); }
};