Issue 5870 - Implement the new ElemHideEmulation filter type

compiled/String.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
@@ skipping 118 matching lines @@
   size_type find(value_type c, size_type pos = 0) const
   {
     for (size_type i = pos; i < length(); ++i)
       if (mBuf[i] == c)
         return i;
     return npos;
   }
 
   size_type find(const String& str, size_type pos = 0) const
   {
-    if (pos > LENGTH_MASK || pos + str.length() > length())
+    return find(str.mBuf, pos, str.length());
+  }
+
+  size_type find(const value_type* str, size_type pos, size_type count) const
+  {
+    if (pos > LENGTH_MASK || pos + count > length())
       return npos;
 
-    if (!str.length())
+    if (!count)
       return pos;
 
-    for (; pos + str.length() <= length(); ++pos)
+    for (; pos + count <= length(); ++pos)
     {
       if (mBuf[pos] == str[0] &&
-          std::memcmp(mBuf + pos, str.mBuf, sizeof(value_type) * str.length()) == 0)
+          std::memcmp(mBuf + pos, str, sizeof(value_type) * count) == 0)
       {
         return pos;
       }
     }
 
     return npos;
   }
 
   size_type rfind(value_type c, size_type pos = npos) const
   {
@@ skipping 281 matching lines @@
     }
   }
 };
 
 #ifdef INSIDE_TESTS
 inline std::ostream& operator<<(std::ostream& os, const OwnedString& str)
 {
   return os << static_cast<const String&>(str);
 }
 #endif