myvtm/ThirdParty/Include/rpcServer/client_util.hpp

#pragma once
#include <tuple>
#if __cplusplus > 201402L
#include <string_view>
using string_view = std::string_view;
#else
#ifdef ASIO_STANDALONE
#include "string_view.hpp"
using namespace nonstd;
#else
#include <boost/utility/string_view.hpp>
using string_view = boost::string_view;
#endif
#endif

#include "codec.h"

namespace rest_rpc {
	inline bool has_error(string_view result) {
		if (result.empty()) {
			return true;
		}			

		rpc_service::msgpack_codec codec;
		auto tp = codec.unpack<std::tuple<int>>(result.data(), result.size());

		return std::get<0>(tp) != 0;
	}

	template<typename T>
	inline T get_result(string_view result) {
		rpc_service::msgpack_codec codec;
		auto tp = codec.unpack<std::tuple<int, T>>(result.data(), result.size());
		return std::get<1>(tp);
	}


	inline std::string get_error_msg(string_view result) {
		rpc_service::msgpack_codec codec;
		auto tp = codec.unpack<std::tuple<int, std::string>>(result.data(), result.size());
		return std::get<1>(tp);
	}

	template<typename T>
	inline T as(string_view result) {
		if (has_error(result)) {
			throw std::logic_error(get_error_msg(result));
		}

		return get_result<T>(result);
	}
}