Merge #13241: scripted-diff: Avoid temporary copies when looping over std::map

9b72c988a0 scripted-diff: Avoid temporary copies when looping over std::map (Ben Woosley)

Pull request description:

  The ::value_type of the std::map/std::multimap/std::unordered_map containers is
  std::pair<const Key, T>. Dropping the const results in an unnecessary copy,
  for example in C++11 range-based loops.

  For this I started with a more general scripted diff, then narrowed it down
  based on the inspection showing that all actual map/multimap/unordered_map
  variables used in loops start with m or have map in the name.

Tree-SHA512: b656d66b69ffa1eb954124aa8ae2bc5436ca50262abefa93bdda55cfcdaffc5ff90cd40539051a2bd06355ba69ddf245265cc8764eebff66d761b3aec06155a9

src/rpc/net.cpp

@@ -475,7 +475,7 @@ static UniValue getnetworkinfo(const JSONRPCRequest& request)
     UniValue localAddresses(UniValue::VARR);
     {
         LOCK(cs_mapLocalHost);
-        for (const std::pair<CNetAddr, LocalServiceInfo> &item : mapLocalHost)
+        for (const std::pair<const CNetAddr, LocalServiceInfo> &item : mapLocalHost)
         {
             UniValue rec(UniValue::VOBJ);
             rec.pushKV("address", item.first.ToString());