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(gmp.info)C++ Interface Random Numbers

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C++ Interface Random Numbers
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 - Class: gmp_randclass
     The C++ class interface to the GMP random number functions uses
     `gmp_randclass' to hold an algorithm selection and current state,
     as per `gmp_randstate_t'.

 - Function:  gmp_randclass::gmp_randclass (void (*RANDINIT)
          (gmp_randstate_t, ...), ...)
     Construct a `gmp_randclass', using a call to the given RANDINIT
     function (Note: Random State Initialization).  The arguments
     expected are the same as RANDINIT, but with `mpz_class' instead of
     `mpz_t'.  For example,

          gmp_randclass r1 (gmp_randinit_default);
          gmp_randclass r2 (gmp_randinit_lc_2exp_size, 32);
          gmp_randclass r3 (gmp_randinit_lc_2exp, a, c, m2exp);

     `gmp_randinit_lc_2exp_size' can fail if the size requested is too
     big, the behaviour of `gmp_randclass::gmp_randclass' is undefined
     in this case (perhaps this will change in the future).

 - Function:  gmp_randclass::gmp_randclass (gmp_randalg_t ALG, ...)
     Construct a `gmp_randclass' using the same parameters as
     `gmp_randinit' (Note: Random State Initialization).  This
     function is obsolete and the above RANDINIT style should be
     preferred.

 - Function: void gmp_randclass::seed (unsigned long int S)
 - Function: void gmp_randclass::seed (mpz_class S)
     Seed a random number generator.  See Note: Random Number
     Functions, for how to choose a good seed.

 - Function: mpz_class gmp_randclass::get_z_bits (unsigned long BITS)
 - Function: mpz_class gmp_randclass::get_z_bits (mpz_class BITS)
     Generate a random integer with a specified number of bits.

 - Function: mpz_class gmp_randclass::get_z_range (mpz_class N)
     Generate a random integer in the range 0 to N-1 inclusive.

 - Function: mpf_class gmp_randclass::get_f ()
 - Function: mpf_class gmp_randclass::get_f (unsigned long PREC)
     Generate a random float F in the range 0 <= F < 1.  F will be to
     PREC bits precision, or if PREC is not given then to the precision
     of the destination.  For example,

          gmp_randclass  r;
          ...
          mpf_class  f (0, 512);   // 512 bits precision
          f = r.get_f();           // random number, 512 bits