[Bug libstdc++/48559] parallel-mode vs C++0x

[singler at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48559

singler@gcc.gnu.org <singler at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011.04.12 19:02:06
                 CC|                            |singler at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #2 from singler at gcc dot gnu.org <singler at gcc dot gnu.org> 2011-04-12 19:02:06 UTC ---
We should try to tweak the algorithms to use just moves.  Since memory
bandwidth often limits parallel performance, it could even be particularly
efficient.

On the other hand, we sometimes need references to elements of the
random-access input sequence(s).  We could always use an iterator, but that
might be inefficient.  And we cannot take the lvalue reference or the address
of a dereferenced random access iterator, can we?  (Although this is
unfortunately done so far in multiseq_selection.h.)  Can we always take the
rvalue reference of a dereferenced random access iterator?

random_shuffle and partition will be the easiest cases, so we should start
there.