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Write contracts + pre/post conditions for all unsafe methods in duration #136
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Write contracts + pre/post conditions for all unsafe methods in duration #136
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That's awesome! Thank you
…ify-rust-std into verify_duration_challenge9
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Awesome! Thanks
Co-authored-by: Celina G. Val <[email protected]>
Co-authored-by: Celina G. Val <[email protected]>
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I don't think we should have anything other than true
as a requires
clause on safe functions.
…r on debug_assert
…omas/verify-rust-std into verify_duration_challenge9
Resolves #72
We added invariants for Nanoseconds and Duration to match the safety conditions for those types.
We add safety requirements to the following methods:
new
,from_secs
,from_millis
,from_micros
,from_nanos
,as_secs
,as_millis
,as_micros
,as_nanos
,subsec_millis
,subsec_micros
,subsec_nanos
,checked_add
,checked_sub
,checked_mul
,checked_div
We additionally add correctness conditions to the following methods:
from_secs
,as_secs
,subsec_millis
,subsec_micros
,subsec_nanos
,as_millis
,as_micros
Support for
kani::Invariant
depends on #87. For the interim we implemented a proxy traitTempInvariant
that exposes the sameis_safe
method. We will update this once #87 is merged.While the safety check for
Duration::as_nanos()
succeeds, we ran into timeouts forDuration::as_nanos()
when we tried to use a correctness contract and we're looking for advice on how to speed up that verification time. We were able to prove it foru16::MAX
, but hit timeouts for larger numbers.We are unsure if the pre-conditions for
Duration::new()
are acceptable because they limit the range of values that you can callDuration::new()
with. However, we think it's reasonable since we limit the values to values that don't panic. Let us know if this is a thing that we should change.By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.