尝试实现parallel_for c ++ 11时出错：OpenMP'for'语句中的错误C3019增量具有不正确的形式

Question

我正在尝试优化遗传算法，但是当使用#pragma omp parallel时，算法运行得非常好。当我将其更改为#pragma omp parallel for时，我收到错误C3019：OpenMP中的增量'for'语句具有不正确的形式。我想要优化的方法是：

vector<unsigned int> decode(genome &gen)
{
    auto num_threads = thread::hardware_concurrency();
    static vector<unsigned int> this_gene(gen.gene_length);
    vector<unsigned int> decoded(NUM_CHARS);

#pragma omp parallel for num_threads(num_threads)

        for (unsigned int gene = 0, count = 0; gene < gen.bits.size(); gene += gen.gene_length, ++count)
        {

            for (unsigned int bit = 0; bit < gen.gene_length; ++bit)
                this_gene[bit] = gen.bits[gene + bit];

            unsigned int val = 0;
            unsigned int multiplier = 1;

            for (unsigned int c_bit = this_gene.size(); c_bit > 0; --c_bit)
            {
                val += this_gene[c_bit - 1] * multiplier;
                multiplier *= 2;
            }
            decoded[count] = val;
        }
    return decoded;
}