Project roadmap and task tracking for the nfx-containers library.

Todo

• Add FlatHashMap and FlatHashSet containers (optimized for low load factors and extreme performance)
  • Tombstone handling for deletions

• Add FastHashMultiMap and FastHashMultiSet containers (indices, graph adjacency lists, grouped data)
  • Support duplicate keys (many-to-many relationships)
  • equalRange() method for retrieving all values for a key
  • Efficient storage with value chaining or bucketing

• Add custom allocator support
  • Allocator template parameter for all containers
  • Arena/pool allocator compatibility

• Add ConcurrentHashMap and ConcurrentHashSet containers (read-optimized for high concurrency scenarios)
  • Thread-safe lock-free or fine-grained locking

• Add BidirectionalHashMap container (bijective mappings, reverse lookups)
  • Bidirectional key-value mapping (lookup by key OR value)
  • Two underlying hash tables with synchronized operations

• Add DynamicPerfectHashMap container (mutable perfect hash map with overflow)
  • Hybrid approach: perfect hash table + overflow buffer for new insertions
  • Automatic rebuild when overflow threshold exceeded
  • O(1) lookups in primary table, fallback to overflow map

In Progress

• NIL

Done ✓

• Add OrderedHashMap and OrderedHashSet containers (config files, JSON parsing, stable iteration, LRU caches)

• Add StackHashMap and StackHashSet with SBO (inline storage with automatic heap fallback)

• Add advanced STL methods (extract(), merge(), contains())

• Add API consistency across all containers (at(), find(), insertOrAssign())