lookahead bitset-ANDNZ.cpp

gistfile1.txt

#include <cstddef>
#include <initializer_list>

template<size_t BITS>
class bitset
{
public:
    bitset() : sizeInBits(BITS), sizeOfWord(sizeof(WORD) * 8), sizeInWords((BITS + (sizeof(WORD) * 8) - 1) / (sizeof(WORD) * 8)) {
        for (size_t i = 0; i < sizeInWords; ++i)
            data[i] = 0;
    }
    bitset(bitset<BITS>& bs) : bitset(bs.sizeInBits, bs.complement) {
        for (size_t i = 0; i < sizeInWords; ++i)
            data[i] = bs.data[i];
    }
    bitset(const bitset<BITS>& bs) : bitset(bs.sizeInBits, bs.complement) {
        for (size_t i = 0; i < sizeInWords; ++i)
            data[i] = bs.data[i];
    }
    bitset(const std::initializer_list<size_t> il) : bitset<BITS>() {
        for (auto i = il.begin(); i != il.end(); ++i)
            set(*i);
    }

    ~bitset() {}

    bitset& set(size_t element, bool v = true) {
        size_t word = element / sizeOfWord;
        size_t bit = element % sizeOfWord;

        WORD value = ((WORD)1) << bit;
        data[word] = (data[word] & ~value) | (v ? value : 0);

        return *this;
    }

    template<size_t B>
    friend inline bool AND(const bitset<B>& input, const bitset<B>& lookaheads) {
        bool result = false;
        for (size_t i = 0; i < lookaheads.sizeInWords; ++i)
            result |= (input.data[i] & lookaheads.data[i]) != 0;
        
        return result;
    }


private:
    typedef unsigned long long WORD;

    const size_t sizeInBits;
    const size_t sizeOfWord;
    const size_t sizeInWords;

    bool complement;
    WORD data[(BITS + (sizeof(WORD) * 8) - 1) / (sizeof(WORD) * 8)];
};

int main(int argc, char *argv[]) {

    bitset<63> input;
    input.set(argc);

    bitset<63> lookahead = {1, 3, 5};
    bool result = AND(input, lookahead) ? 0 : 1;

    return result;
}