diff --git a/src/util.h b/src/util.h
index 4751efb29..4a0a37fe5 100644
--- a/src/util.h
+++ b/src/util.h
@@ -1,317 +1,331 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 /**
  * Server/client environment: argument handling, config file parsing,
  * thread wrappers, startup time
  */
 #ifndef BITCOIN_UTIL_H
 #define BITCOIN_UTIL_H
 
 #if defined(HAVE_CONFIG_H)
 #include <config/bitcoin-config.h>
 #endif
 
 #include <compat.h>
 #include <fs.h>
 #include <logging.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <utiltime.h>
 
 #include <boost/signals2/signal.hpp>
 #include <boost/thread/condition_variable.hpp> // for boost::thread_interrupted
 
 #include <atomic>
 #include <cstdint>
 #include <exception>
 #include <map>
 #include <set>
 #include <string>
 #include <unordered_set>
 #include <vector>
 
 // Application startup time (used for uptime calculation)
 int64_t GetStartupTime();
 
 /** Signals for translation. */
 class CTranslationInterface {
 public:
     /** Translate a message to the native language of the user. */
     boost::signals2::signal<std::string(const char *psz)> Translate;
 };
 
 extern CTranslationInterface translationInterface;
 
 extern const char *const BITCOIN_CONF_FILENAME;
 extern const char *const BITCOIN_PID_FILENAME;
 
 /**
  * Translation function: Call Translate signal on UI interface, which returns a
  * boost::optional result. If no translation slot is registered, nothing is
  * returned, and simply return the input.
  */
 inline std::string _(const char *psz) {
     boost::optional<std::string> rv = translationInterface.Translate(psz);
     return rv ? (*rv) : psz;
 }
 
 void SetupEnvironment();
 bool SetupNetworking();
 
 template <typename... Args> bool error(const char *fmt, const Args &... args) {
     LogPrintf("ERROR: " + tfm::format(fmt, args...) + "\n");
     return false;
 }
 
 void PrintExceptionContinue(const std::exception *pex, const char *pszThread);
 void FileCommit(FILE *file);
 bool TruncateFile(FILE *file, unsigned int length);
 int RaiseFileDescriptorLimit(int nMinFD);
 void AllocateFileRange(FILE *file, unsigned int offset, unsigned int length);
 bool RenameOver(fs::path src, fs::path dest);
 bool LockDirectory(const fs::path &directory, const std::string lockfile_name,
                    bool probe_only = false);
 bool DirIsWritable(const fs::path &directory);
 
 /**
  * Release all directory locks. This is used for unit testing only, at runtime
  * the global destructor will take care of the locks.
  */
 void ReleaseDirectoryLocks();
 
 bool TryCreateDirectories(const fs::path &p);
 fs::path GetDefaultDataDir();
 // The blocks directory is always net specific.
 const fs::path &GetBlocksDir();
 const fs::path &GetDataDir(bool fNetSpecific = true);
 void ClearDatadirCache();
 fs::path GetConfigFile(const std::string &confPath);
 #ifndef WIN32
 fs::path GetPidFile();
 void CreatePidFile(const fs::path &path, pid_t pid);
 #endif
 #ifdef WIN32
 fs::path GetSpecialFolderPath(int nFolder, bool fCreate = true);
 #endif
 void runCommand(const std::string &strCommand);
 
 inline bool IsSwitchChar(char c) {
 #ifdef WIN32
     return c == '-' || c == '/';
 #else
     return c == '-';
 #endif
 }
 
 enum class OptionsCategory {
     OPTIONS,
     CONNECTION,
     WALLET,
     WALLET_DEBUG_TEST,
     ZMQ,
     DEBUG_TEST,
     CHAINPARAMS,
     NODE_RELAY,
     BLOCK_CREATION,
     RPC,
     GUI,
     COMMANDS,
     REGISTER_COMMANDS
 };
 
 class ArgsManager {
 protected:
     friend class ArgsManagerHelper;
 
     mutable CCriticalSection cs_args;
     std::map<std::string, std::vector<std::string>> m_override_args;
     std::map<std::string, std::vector<std::string>> m_config_args;
     std::string m_network;
     std::set<std::string> m_network_only_args;
     std::map<std::pair<OptionsCategory, std::string>,
              std::pair<std::string, bool>>
         m_available_args;
 
     void ReadConfigStream(std::istream &stream);
 
 public:
     ArgsManager();
 
     /**
      * Select the network in use
      */
     void SelectConfigNetwork(const std::string &network);
 
     void ParseParameters(int argc, const char *const argv[]);
     void ReadConfigFiles();
 
     /**
      * Log warnings for options in m_section_only_args when they are specified
      * in the default section but not overridden on the command line or in a
      * network-specific section in the config file.
      */
     void WarnForSectionOnlyArgs();
 
     /**
      * Return a vector of strings of the given argument
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @return command-line arguments
      */
     std::vector<std::string> GetArgs(const std::string &strArg) const;
 
     /**
      * Return true if the given argument has been manually set.
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @return true if the argument has been set
      */
     bool IsArgSet(const std::string &strArg) const;
 
     /**
      * Return true if the argument was originally passed as a negated option,
      * i.e. -nofoo.
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @return true if the argument was passed negated
      */
     bool IsArgNegated(const std::string &strArg) const;
 
     /**
      * Return string argument or default value.
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @param default (e.g. "1")
      * @return command-line argument or default value
      */
     std::string GetArg(const std::string &strArg,
                        const std::string &strDefault) const;
 
     /**
      * Return integer argument or default value.
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @param default (e.g. 1)
      * @return command-line argument (0 if invalid number) or default value
      */
     int64_t GetArg(const std::string &strArg, int64_t nDefault) const;
 
     /**
      * Return boolean argument or default value.
      *
      * @param strArg Argument to get (e.g. "-foo")
      * @param default (true or false)
      * @return command-line argument or default value
      */
     bool GetBoolArg(const std::string &strArg, bool fDefault) const;
 
     /**
      * Set an argument if it doesn't already have a value.
      *
      * @param strArg Argument to set (e.g. "-foo")
      * @param strValue Value (e.g. "1")
      * @return true if argument gets set, false if it already had a value
      */
     bool SoftSetArg(const std::string &strArg, const std::string &strValue);
 
     /**
      * Set a boolean argument if it doesn't already have a value.
      *
      * @param strArg Argument to set (e.g. "-foo")
      * @param fValue Value (e.g. false)
      * @return true if argument gets set, false if it already had a value
      */
     bool SoftSetBoolArg(const std::string &strArg, bool fValue);
 
     // Forces a arg setting, used only in testing
     void ForceSetArg(const std::string &strArg, const std::string &strValue);
 
     // Forces a multi arg setting, used only in testing
     void ForceSetMultiArg(const std::string &strArg,
                           const std::string &strValue);
 
     /**
      * Looks for -regtest, -testnet and returns the appropriate BIP70 chain
      * name.
      * @return CBaseChainParams::MAIN by default; raises runtime error if an
      * invalid combination is given.
      */
     std::string GetChainName() const;
 
     /**
      * Add argument
      */
     void AddArg(const std::string &name, const std::string &help,
                 const bool debug_only, const OptionsCategory &cat);
 
     // Remove an arg setting, used only in testing
     void ClearArg(const std::string &strArg);
 
     /**
      * Get the help string
      */
     std::string GetHelpMessage();
 };
 
 extern ArgsManager gArgs;
 
 /**
  * @return true if help has been requested via a command-line arg
  */
 bool HelpRequested(const ArgsManager &args);
 
 /**
  * Format a string to be used as group of options in help messages.
  *
  * @param message Group name (e.g. "RPC server options:")
  * @return the formatted string
  */
 std::string HelpMessageGroup(const std::string &message);
 
 /**
  * Format a string to be used as option description in help messages.
  *
  * @param option Option message (e.g. "-rpcuser=<user>")
  * @param message Option description (e.g. "Username for JSON-RPC connections")
  * @return the formatted string
  */
 std::string HelpMessageOpt(const std::string &option,
                            const std::string &message);
 
 /**
  * Return the number of physical cores available on the current system.
  * @note This does not count virtual cores, such as those provided by
  * HyperThreading when boost is newer than 1.56.
  */
 int GetNumCores();
 
 void RenameThread(const char *name);
 
 /**
  * .. and a wrapper that just calls func once
  */
 template <typename Callable> void TraceThread(const char *name, Callable func) {
     std::string s = strprintf("bitcoin-%s", name);
     RenameThread(s.c_str());
     try {
         LogPrintf("%s thread start\n", name);
         func();
         LogPrintf("%s thread exit\n", name);
     } catch (const boost::thread_interrupted &) {
         LogPrintf("%s thread interrupt\n", name);
         throw;
     } catch (const std::exception &e) {
         PrintExceptionContinue(&e, name);
         throw;
     } catch (...) {
         PrintExceptionContinue(nullptr, name);
         throw;
     }
 }
 
 std::string CopyrightHolders(const std::string &strPrefix);
 
+namespace util {
+
+//! Simplification of std insertion
+template <typename Tdst, typename Tsrc>
+inline void insert(Tdst &dst, const Tsrc &src) {
+    dst.insert(dst.begin(), src.begin(), src.end());
+}
+template <typename TsetT, typename Tsrc>
+inline void insert(std::set<TsetT> &dst, const Tsrc &src) {
+    dst.insert(src.begin(), src.end());
+}
+
+} // namespace util
+
 #endif // BITCOIN_UTIL_H