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digitalmars.D.bugs - [Issue 10900] New: Mersenne Twister should have a 64-bit (ulong) version


           Summary: Mersenne Twister should have a 64-bit (ulong) version
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: joseph.wakeling webdrake.net

--- Comment #0 from Joseph Rushton Wakeling <joseph.wakeling webdrake.net>
2013-08-26 04:43:25 PDT ---
Boost.Random's Mersenne Twister implementation defines a 64-bit as well as
32-bit version:

#if !defined(BOOST_NO_INT64_T) && !defined(BOOST_NO_INTEGRAL_INT64_T)
typedef mersenne_twister_engine<uint64_t,64,312,156,31,
    UINT64_C(6364136223846793005)> mt19937_64;

This should be ported to Phobos.

It will require some tweaks to the MersenneTwisterEngine design, as it takes
more template parameters than std.random's 32-bit version.  Compare Phobos,
with 11 different template parameters apart from the UIntType:

struct MersenneTwisterEngine(UIntType, size_t w, size_t n, size_t m, size_t r,
                             UIntType a, size_t u, size_t s,
                             UIntType b, size_t t,
                             UIntType c, size_t l)

with Boost (13 template parameters besides the UIntType):

template<class UIntType,
         std::size_t w, std::size_t n, std::size_t m, std::size_t r,
         UIntType a, std::size_t u, UIntType d, std::size_t s,
         UIntType b, std::size_t t,
         UIntType c, std::size_t l, UIntType f>
class mersenne_twister_engine

See: http://www.boost.org/doc/libs/1_54_0/boost/random/mersenne_twister.hpp

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Aug 26 2013