[Bug libstdc++/57920] [c++11] Linux: std::random_device reads too much from /dev/urandom

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57920

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Created attachment 30534
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30534&action=edit
Draft mainline patch