Struct Gen 

pub struct Gen { /* private fields */ }

Gen represents a PRNG.

It is the source of randomness from which QuickCheck will generate values. An instance of Gen is passed to every invocation of Arbitrary::arbitrary, which permits callers to use lower level RNG routines to generate values.

It is unspecified whether this is a secure RNG or not. Therefore, callers should assume it is insecure.

Implementations

impl Gen

pub fn new(size: usize) -> Gen

Returns a Gen with a random seed and the given size configuration.

The size parameter controls the size of random values generated. For example, it specifies the maximum length of a randomly generated vector, but is and should not be used to control the range of a randomly generated number. (Unless that number is used to control the size of a data structure.)

pub fn from_size_and_seed(size: usize, seed: u64) -> Gen

Returns a Gen with the given seed and a default size configuration.

Two Gens created with the same seed will generate the same values. Though the values may vary between QuickCheck releases.

The size parameter controls the size of random values generated. For example, it specifies the maximum length of a randomly generated vector, but is and should not be used to control the range of a randomly generated number. (Unless that number is used to control the size of a data structure.)

pub fn size(&self) -> usize

Returns the size configured with this generator.

pub fn choose<'a, T>(&mut self, slice: &'a [T]) -> Option<&'a T>

Choose among the possible alternatives in the slice given. If the slice is empty, then None is returned. Otherwise, a non-None value is guaranteed to be returned.