Issue 5141 - Generalize Map class to allow non-strings as keys

compiled/StringMap.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 14 matching lines @@
 namespace StringMap_internal
 {
   struct StringSetEntry
   {
     typedef DependentString key_type;
     typedef const String& key_type_cref;
     typedef size_t size_type;
 
     key_type first;
 
-    StringSetEntry(key_type_cref key = DependentString())

[sergei, 2017/12/04 14:26:09]

here and below the default value for `key` could be key_type() or even some
INVALID_KEY, where INVALID_KEY is
static const key_type INVALID_KEY = DependentString();

[Wladimir Palant, 2017/12/04 18:28:48]

It's non-trivial to initialize that static member, so I went with key_type()
instead.

+    StringSetEntry(key_type_cref key = key_type())
     {
       if (!key.is_invalid())
         first.reset(key);
     }
 
     bool equals(key_type_cref other) const
     {
       return first.equals(other);
     }
 
@@ skipping 41 matching lines @@
       super::erase();
       second = value_type();
     }
   };
 }
 
 using StringSet = Set<StringMap_internal::StringSetEntry>;
 
 template<typename Value>
 using StringMap = Map<StringMap_internal::StringMapEntry<Value>>;