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[Bug libstdc++/66302] Wrong output sequence of double precision uniform C++ RNG distribution
- From: "redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 27 May 2015 10:11:45 +0000
- Subject: [Bug libstdc++/66302] Wrong output sequence of double precision uniform C++ RNG distribution
- Auto-submitted: auto-generated
- References: <bug-66302-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66302
--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Andrey Kolesov from comment #0)
> Double precision uniform distribution of C++ random number generators from
> libstdc++ produces sequence which is significantly different from floating
> point and integer (direct engine) generators.
> Double precision sequence contains only every second (odd: 1,3,5,7...)
> element from float and integer sequences. Generally generator output
> shouldn't depend on output data type up to precision bounds.
Where does it say that in the standard?
Your code says:
/* All three sequences expected to be equal up to precision bounds */
Where does the standard say you should expect that?