[v3] PR 35256

[Johannes Singler]

Benjamin Kosnik wrote:
> Updates for broken links, more elaborate markup. As part of this, I
> corrected the configuration/tuning section to take into account the new
> __gnu_parallel::_Settings approach.

Thanks for the docs.
Some comments:

>    <listitem><para><code>std::(multi_)map/set<T>::(multi_)map/set(Iterator begin, Iterator end)</code> (bulk construction)</para></listitem>
>    <listitem><para><code>std::(multi_)map/set<T>::insert(Iterator begin, Iterator end)</code> (bulk insertion)</para></listitem>

The dictionary bulk insertion was taken out by Paolo, but I have a patch 
almost ready to reinclude it. But this has to be discussed first.

> +  // Explicitly set number of threads.
> +  const int threads_wanted = 20;
> +  omp_set_dynamic(false);
> +  omp_set_num_threads(threads_wanted);
> +  if (omp_get_num_threads() != threads_wanted)
> +    abort();

omp_get_num_threads() is (unfortunately) not the counterpart of 
omp_set_num_threads(), and only >1 in a parallel region. 
omp_get_max_threads() is better, but AFAIK not too much is guaranteed 
according to the OpenMP specification.

-- Johannes