feat: Add a fork() method #49
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| RNG.try_with(|rng| { | ||
| let current = rng.replace(Rng(0)); | ||
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| let mut restore = RestoreOnDrop { rng, current }; |
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can we be sure that this doesn't corrupt the Rng in case of a panic? or doesn't that matter because the u64 seed doesn't have invalid states and thus we can just do that anyways? why isn't that an exposed functionality/method of Cell?
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I don't think this is an issue, since with &mut there shouldn't be any way to corrupt it with uninitialized data.
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ok, what is the function of the RestoreOnDrop here, why is it necessary? Or better, how is it supposed to work, because currently, the interaction seems to be a bit unclear to me. This isn't actually a blocker to this PR, but I would appreciate better documentation for this abstraction combo.
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In order to use the Rng stored in the thread-local variable, the Rng needs to be replaced with a zero value and moved out, then moved back in once the operation is done. The RestoreOnDrop guard ensures that it's moved back in even in the event of a panic (which can happen if the range bounds are invalid), preventing the thread-local variable from being set to 0 and causing a loss of entropy.
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I'd appreciate it if we would simply define the Rng to be Clone + Copy, which would allow us to use more convenient methods on Cell<Rng>.
- **Breaking:** Remove interior mutability from `Rng`. (#47) - Add a `fork()` method. (#49) - Add a `no_std` mode. (#50) - Add an iterator selection function. (#51) - Add a `choose_multiple()` function for sampling several elements from an iterator. (#55) - Use the `getrandom` crate for seeding on WebAssembly targets if the `js` feature is enabled. (#60)
Closes #36 by adding a
fork()method that can be used to clone the RNG with a new seed. This strategy is also used inRng::new()to fork from the global RNG.