Issue 6360 - Add support of MSVS

compiled/subscription/Subscription.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <cstdio>
 #include <cstdlib>
+#include <random>
 
 #include "Subscription.h"
 #include "DownloadableSubscription.h"
 #include "UserDefinedSubscription.h"
 #include "../StringMap.h"
 
 ABP_NS_USING
 
 namespace
 {
@@ skipping 58 matching lines @@
     result.append(u'\n');
   }
   return result;
 }
 
 Subscription* Subscription::FromID(const String& id)
 {
   if (id.empty())
   {
     // Generate a new random ID
-    unsigned int seed = knownSubscriptions.size();
+    std::mt19937 gen(knownSubscriptions.size());

[sergei, 2018/02/06 13:07:29]

It slightly differs from rand_r, what results in additional ~200 bytes in
compiled.js.

     OwnedString randomID(u"~user~000000"_str);
     do
     {
-      int number = rand_r(&seed);
+      int number = gen();
       for (int i = randomID.length() - 6; i < randomID.length(); i++)
       {
         randomID[i] = '0' + (number % 10);
         number /= 10;
       }
     } while (knownSubscriptions.find(randomID));
     return FromID(randomID);
   }
 
   auto knownSubscription = knownSubscriptions.find(id);
@@ skipping 11 matching lines @@
 
   // This is a hack: we looked up the entry using id but create it using
   // subscription->mID. This works because both are equal at this point.
   // However, id refers to a temporary buffer which will go away.
   enter_context("Adding to known subscriptions");
   knownSubscription.assign(subscription->mID, subscription.get());
   exit_context();
 
   return subscription.release();
 }