Function unique

test/schedule_test.cpp:231–236

template <class T>
static std::vector<T> unique(std::vector<T> x)
{
    std::sort(x.begin(), x.end());
    x.erase(std::unique(x.begin(), x.end()), x.end());
    return x;
}

static std::vector<std::size_t> get_wait_for(std::vector<std::size_t> wait_for)
{