v0.3.0

🆕 New Features

• SubNetting method enhancement : Added MethodSubnetMask for subnet division based on mask prefix length
• Enhanced API : Added StartIP() and EndIP() methods for more granular IP range access
• String() method : New method for string representation (CIDR() method remains unchanged)
• EqualFold() method : Format-agnostic comparison method that ignores special format differences
• IP increment/decrement : New IPIncr2 and IPDecr2 methods that don't modify input IP
• Fine-grained IP type detection : New IsPureIPv6() method for precise IPv6 detection (excluding IPv4-mapped)

⚠️ Breaking Changes

• Equal() method : Now compares both IP and mask (more strict comparison)
• Mask() method : Return type changed from net.IP to net.IPMask
• MaskSize() method : Removed from the API (use c.Mask().Size() instead)
• Broadcast() method : Returns nil for pure IPv6 addresses (only valid for IPv4 and IPv4-mapped)

🔧 Optimizations

• Loop exit conditions optimization
• Enhanced error handling
• IPv4/IPv6 compatibility fixes
• Code refactoring