RPC argument metadata and typed accessors

501    template <typename R>
502    auto MaybeArg(std::string_view key) const
503    {
504        auto i{GetParamIndex(key)};
505        // Return optional argument (without default).
506        if constexpr (std::is_trivially_copyable_v<R>) {
507            // Return trivially copyable types by value, wrapped in optional.
508            return ArgValue<std::optional<R>>(i);
509        } else {
510            // Return other types by pointer.
511            return ArgValue<const R*>(i);
512        }
513    }
514    std::string ToString() const;
515    /** Return the named args that need to be converted from string to another JSON type */
516    UniValue GetArgMap() const;
517    /** If the supplied number of args is neither too small nor too high */
518    bool IsValidNumArgs(size_t num_args) const;
519    //! Return list of arguments and whether they are named-only.
520    std::vector<std::pair<std::string, bool>> GetArgNames() const;
521    const std::string& GetDescription() const { return m_description; }
522    const std::vector<RPCArg>& GetArgs() const { return m_args; }
523    const RPCResults& GetResults() const { return m_results; }
524
525    const std::string m_name;
526
527private:
528    const RPCMethodImpl m_fun;
529    const std::string m_description;
530    const std::vector<RPCArg> m_args;
531    const RPCResults m_results;
532    const RPCExamples m_examples;
533    mutable const JSONRPCRequest* m_req{nullptr}; // A pointer to the request for the duration of m_fun()
534    template <typename R>
535    R ArgValue(size_t i) const;
536    //! Return positional index of a parameter using its name as key.
537    size_t GetParamIndex(std::string_view key) const;
538};
539
540/**
541 * Push warning messages to an RPC "warnings" field as a JSON array of strings.
542 *
543 * @param[in] warnings  Warning messages to push.
544 * @param[out] obj      UniValue object to push the warnings array object to.
545 */
546void PushWarnings(const UniValue& warnings, UniValue& obj);
547void PushWarnings(const std::vector<bilingual_str>& warnings, UniValue& obj);
548
549std::vector<RPCResult> ScriptPubKeyDoc();
550
551/***
552 * Get the target for a given block index.
553 *
554 * @param[in] blockindex    the block
555 * @param[in] pow_limit     PoW limit (consensus parameter)
556 *
557 * @return  the target
558 */
559uint256 GetTarget(const CBlockIndex& blockindex, uint256 pow_limit);
560
561#endif // BITCOIN_RPC_UTIL_H
562