Parallel Loops in C++

I wonder if there is a light, straight forward way to have loops such as for and range based-for loops compute in parallel in C++. How would you implement such a thing? From Scala I know the map, filter and foreach functions and maybe it would also be possible to perform these in parallel? Is there an easy way to achieve this in C++?

My primary platform is Linux, but it would be nice if it worked cross-platform.

With the parallel algorithms in C++17 we can now use:

std::vector<std::string> foo;
std::for_each(
    std::execution::par_unseq,
    foo.begin(),
    foo.end(),
    [](auto&& item)
    {
        //do stuff with item
    });

to compute loops in parallel. The first parameter specifies the execution policy

What is your platform? You can look at OpenMP, though it's not a part of C++. But it is widely supported by compilers.

As for range-based for loops, see, e.g., Using OpenMP with C++11 range-based for loops?.

I've also seen few documents at http://www.open-std.org that indicate some efforts to incorporate parallel constructs/algorithms into future C++, but don't know what's their current status.

UPDATE

Just adding some exemplary code:

template <typename RAIter>
void loop_in_parallel(RAIter first, RAIter last) {
   const size_t n = std::distance(first, last);

   #pragma omp parallel for
   for (size_t i = 0; i < n; i++) {
       auto& elem = *(first + i);
       // do whatever you want with elem
    }
}

The number of threads can be set at runtime via the OMP_NUM_THREADS environment variable.