Issue 5870 - Implement the new ElemHideEmulation filter type

compiled/Utils.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/>.
  */
 
 #pragma once
 
 #include <string>
 
 #include "base.h"
 #include "String.h"
 
 ABP_NS_BEGIN
 
+// the length of a null terminated character sequence (string)
+template<typename T, size_t N>
+constexpr size_t str_length_of(T (&)[N])
+{
+  return N - 1;
+}
+
 std::wstring StdWStringFromString(const String& str);
 
 ABP_NS_END