Issue 6064 - Put C++ code into a configurable namespace

compiled/user-config.h

 /*
  * 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/>.
+ * along with Adblock Plus. If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
-#if defined(__EMSCRIPTEN__)
-#include <emscripten.h>
-#define BINDINGS_EXPORTED EMSCRIPTEN_KEEPALIVE
+// ABP_NS, ABP_NS_BEGIN, ABP_NS_END and ABP_NS_USING allow to put the code of
+// this library into ABP_NS namespace. The easiest way to do it is to define
+// ABP_NS on the next line.
+//#define ABP_NS abp_core
+#if defined(ABP_NS)
+#define ABP_NS_BEGIN namespace ABP_NS {
+#define ABP_NS_END }
+#define ABP_NS_USING using namespace ABP_NS;
 #else
-#define BINDINGS_EXPORTED
+#define ABP_NS
+#define ABP_NS_BEGIN
+#define ABP_NS_END
+#define ABP_NS_USING
 #endif
+