@rand()
@rand is an impure function returning a random number between 0 and 1 (included).
@rand is similar to @random but rely on a different algorithm to generate the random numbers.
See also random related functions: @rand, @rand_int, @random, @rnd_bernoulli, @rnd_binomial, @rnd_exponential, @rnd_gamma, @rnd_geometric, @rnd_normal, @rnd_uniform_float, @rnd_uniform_int