cbitset — High-Performance Dynamic Bitset for C

A fast, clean, zero-dependency, pure C99 dynamic bitset with a complete feature set.

• Arbitrary size
• Constant-time popcount, find_first, find_next
• Safe logical operations (&, |, ^, ~)
• In-place left/right shifts
• Canonical representation (unused bits always zero → memcmp safe)
• String conversion (MSB-first, like 0b...)
• Uses GCC/Clang builtins (__builtin_popcountll, __builtin_ctzll) for maximum speed

Perfect for:

• Compilers / interpreters
• Cryptography
• Sparse sets
• Bit-level algorithms
• Embedded systems (when you need speed)

Why this one?

Feature	cbitset	std::bitset	boost::dynamic_bitset	Most GitHub impls
Dynamic size	Yes	No	Yes	Sometimes
Zero dependencies	Yes	C++	Boost	Sometimes
Pure C99	Yes	No	No	Rare
Unused bits normalized	Yes	Yes	Yes	Often buggy
find_next + ctzll	Yes	No	Yes	Rare
Clean API + full ops	Yes	Yes	Yes	Incomplete