It is not "solved" at all. std::bitset has terrible properties and an awful interface. 1. No dynamic resize, have to know size at compile time or allocate base

It is not "solved" at all. std::bitset has terrible properties and an awful interface. 1. No dynamic resize, have to know size at compile time or allocate based on max expectations. And yes, std::vector<bool> sucks too. 2. Despite being only statically sized, several classes of bugs are not prevented at compile-time. For example: std::bitset<4> fail1{"10001"}; // This produces a value of 0b1000, no warnings or exceptions thrown std::bitset<10> fail2; fail2.set(11); // Exception at runtime. Why is this not a static_assert? 3. Size is implementation defined. std::bitset<1> can use up to 8 bytes depending on compiler/platform. 4. Debug performance is 20x slower than Release. In many cases you are going from what would be a single assembly instruction to multiple function calls. 5. Limited options for accessing underlying storage efficiently (for serialization, etc). to_ullong() will work up to 64 bits, but beyond that it will throw exceptions. 6. Uses exceptions. This is still a deal breaker for many. 7. Cannot toggle a range of bits at once. It's either one or all.