math/rand/v2 is an unsupported randomness source

[awnumar]

With the release of Go 1.22, there's a new version of the math/rand package.

At present, it's not possible to use a randomness source created by v2 with jitterbug, e.g.

t := jitterbug.New(1 * time.Minute, jitterbug.Norm{
	Source: mrandv2.New(...),
	Stdev: 1 * time.Second,
})

this fails because math/rand/v2.Rand != math/rand.Rand.

This isn't a huge issue, but thought it's worth flagging anyways. Perhaps one way to solve this would be to update implementations of the Jitter interface to accept an interface instead of *math.Rand

type RandomSource interface {
	NormFloat64() float64
        ...
}

type Norm struct {
	Source      RandomSource
	Mean, Stdev time.Duration
}

or maybe even:

type RandomSource interface {
	mrand.Rand | mrandv2.Rand
}

though I'm not sure how well that'd work with pointer receivers as I've not tested it.

[lthibault]

Thanks for flagging this! Proposed solution sounds good to me as well.

Any chance you could open a PR for this? I'll happily merge it in.