ng algorithm.
As 
<a href="https://en.cppreference.com/w/cpp/error/errc" class="api-reference" target="_blank"><i class="fa fa-book" aria-hidden="true"></i> <code>std::errc</code></a>
 exactly maps POSIX <code>errno</code>, on all platforms

<a href="https://en.cppreference.com/w/cpp/error/generic_category" class="api-reference" target="_blank"><i class="fa fa-book" aria-hidden="true"></i> <code>std::generic_category</code></a>
 error codes are matched by this function.
Only on POSIX platforms only are 
<a 