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## Unreleased
Released YYYY-MM-DD.
### Added
* TODO (or remove section if none)
### Changed
* TODO (or remove section if none)
### Deprecated
* TODO (or remove section if none)
### Removed
* TODO (or remove section if none)
### Fixed
* TODO (or remove section if none)
### Security
* TODO (or remove section if none)
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## 1.3.2
Released 2023-10-30.
### Added
* Added `Arbitrary` implementations for `Arc<[T]>` and
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## 1.3.1
Released 2023-10-11.
### Fixed
* Fixed an issue with generating collections of collections in
`arbitrary_take_rest` where `<Vec<Vec<u8>>>::arbitrary_take_rest` would never
generate `vec![vec![]]` for example. See
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## 1.3.0
Released 2023-03-13.
### Added
* Added the ability to manually specify derived trait bounds for
details.
### Fixed
* Fixed minimal versions correctness for `syn`.
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## 1.2.3
Released 2023-01-20.
### Fixed
* The `derive(Arbitrary)` will now annotate the generated `impl`s with a `#[automatically_derived]`
attribute to indicate to e.g. clippy that lints should not fire for the code within the derived
implementation.
## 1.2.2
Released 2023-01-03.
### Fixed
* Ensured that `arbitrary` and `derive_arbitrary` versions are synced up so that
they don't, e.g., emit generated code that depends on newer versions of
`arbitrary` than the one currently in
## 1.2.1
### Fixed
* Fixed an issue where `std::thread_local!` macro invocations in derive code
were not fully prefixed, causing confusing build errors in certain situations.
## 1.2.0
Released 2022-10-20.
### Added
* Support custom arbitrary implementation for fields on
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## 1.1.6
Released 2022-09-20.
### Fixed
* Fixed a potential panic due to an off-by-one error in the `Arbitrary`
implementation for `std::ops::Bound<T>`.
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## 1.1.5
Released 2022-09-08.
### Added
* Implemented `Arbitrary` for `std::ops::Bound<T>`.
### Fixed
* Fixed a bug where `Unstructured::int_in_range` could return out-of-range
integers when generating arbitrary signed integers.
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## 1.1.4
Released 2022-08-29.
### Added
* Implemented `Arbitrary` for `Rc<str>` and `Arc<str>`
### Changed
* Allow overriding the error type in `arbitrary::Result`
* The `Unstructured::arbitrary_loop` method will consume fewer bytes of input
now.
### Fixed
* Fixed a bug where `Unstructured::int_in_range` could return out-of-range
integers.
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## 1.1.3
Released 2022-06-23.
### Fixed
* Fixed some potential (but highly unlikely) name-clashes inside
`derive(Arbitrary)`'s generated
* Fixed an edge case where `derive(Arbitrary)` for recursive types that detected
an overflow would not reset the overflow
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## 1.1.2
Released 2022-06-16.
### Fixed
* Fixed a warning inside `derive(Arbitrary)`-generated
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## 1.1.1
Released 2022-06-14.
### Fixed
* Fixed a stack overflow when using `derive(Arbitrary)` with recursive types and
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## 1.1.0
Released 2022-02-09.
### Added
* Added the `Unstructured::ratio` method to generate a boolean that is `true` at
the given rate.
* Added the `Unstructured::arbitrary_loop` method to call a function an
arbitrary number of times.
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## 1.0.3
Released 2021-11-20.
### Fixed
* Fixed documentation for `Unstructured::fill_bytes`. We forgot to update this
behavior changed.
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## 1.0.2
Released 2021-08-25.
### Added
* `Arbitrary` impls for `HashMap`s and `HashSet`s with custom `Hasher`s
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## 1.0.1
Released 2021-05-20.
### Added
* `Arbitrary` impls for all arrays using const generics [#55](https://github.com/rust-fuzz/arbitrary/pull/55)
* `Arbitrary` impls for `Ipv4Addr` and `Ipv6Addr` [#84](https://github.com/rust-fuzz/arbitrary/pull/84)
### Fixed
* Use fewer bytes for `Unstructured::int_in_range()` [#80](https://github.com/rust-fuzz/arbitrary/pull/80)
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## 1.0.0
Released 2020-02-24.
See 1.0.0-rc1 and 1.0.0-rc2 for changes since 0.4.7, which was the last main
line release.
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## 1.0.0-rc2
Released 2021-02-09.
### Added
* The `Arbitrary` trait is now implemented for `&[u8]`. [#67](https://github.com/rust-fuzz/arbitrary/pull/67)
### Changed
* Rename `Unstructured#get_bytes` to `Unstructured#bytes`. [#70](https://github.com/rust-fuzz/arbitrary/pull/70)
* Passing an empty slice of choices to `Unstructured#choose` returns an error. Previously it would panic. [71](https://github.com/rust-fuzz/arbitrary/pull/71)
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## 1.0.0-rc1
Released 2020-11-25.
### Added
* The `Arbitrary` trait is now implemented for `&str`. [#63](https://github.com/rust-fuzz/arbitrary/pull/63)
### Changed
* The `Arbitrary` trait now has a lifetime parameter, allowing `Arbitrary` implementations that borrow from the raw input (e.g. the new `&str` implementaton). The `derive(Arbitrary)` macro also supports deriving `Arbitrary` on types with lifetimes now. [#63](https://github.com/rust-fuzz/arbitrary/pull/63)
### Removed
* The `shrink` method on the `Arbitrary` trait has been removed.
We have found that, in practice, using [internal reduction](https://drmaciver.github.io/papers/reduction-via-generation-preview.pdf) via approaches like `cargo fuzz tmin`, where the raw input bytes are reduced rather than the `T: Arbitrary` type constructed from those raw bytes, has the best efficiency-to-maintenance ratio. To the best of our knowledge, no one is relying on or using the `Arbitrary::shrink` method. If you *are* using and relying on the `Arbitrary::shrink` method, please reach out by [dropping a comment here](https://github.com/rust-fuzz/arbitrary/issues/62) and explaining how you're using it and what your use case is. We'll figure out what the best solution is, including potentially adding shrinking functionality back to the `arbitrary` crate.
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## 0.4.7
Released 2020-10-14.
### Added
* Added an optimization to avoid unnecessarily consuming bytes from the
underlying data when there is only one possible choice in
`Unstructured::{int_in_range, choose, etc..}`.
* Added license files to the derive crate.
### Changed
* The `Arbitrary` implementation for `std::time::Duration` should now be faster
and produce durations with a more-uniform distribution of nanoseconds.
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## 0.4.6
Released 2020-08-22.
### Added
* Added the `Unstructured::peek_bytes` method.
### Changed
* Test case reduction via `cargo fuzz tmin` should be much more effective at
reducing the sizes of collections now. (See
for details.)
* Fuzzing with mutation-based fuzzers (like libFuzzer) should be more efficient
messages for details)
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## 0.4.5
Released 2020-06-18.
### Added
* Implement `Arbitrary` for zero length arrays.
* Implement `Arbitrary` for `Range` and `RangeInclusive`.
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## 0.4.4
Released 2020-04-29.
### Fixed
* Fixed the custom derive for enums when used via its full path (like
`#[derive(arbitrary::Arbitrary)]` rather than like `#[derive(Arbitrary)]`).
## 0.4.3
Released 2020-04-28.
### Fixed
* Fixed the custom derive when used via its full path (like
`#[derive(arbitrary::Arbitrary)]` rather than like `#[derive(Arbitrary)]`).
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## 0.4.2
Released 2020-04-17.
### Changed
* We forgot to release a new version of the `derive_arbitrary` crate last
release. This release fixes that and so the `synstructure` dependency is
finally actually removed in the cargo releases.
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## 0.4.1
Released 2020-03-18.
### Removed
* Removed an internal dependency on the `synstructure` crate when the `derive`
feature is enabled. This should not have any visible downstream effects other
than faster build times!
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## 0.4.0
Released 2020-01-22.
This is technically a breaking change, but we expect that nearly everyone should
be able to upgrade without any compilation errors. The only exception is if you
were implementing the `Arbitrary::size_hint` method by hand. If so, see the
"changed" section below and the [API docs for
`Arbitrary::shrink`](https://docs.rs/arbitrary/0.4.0/arbitrary/trait.Arbitrary.html#method.size_hint)
for details.
### Added
* Added [the `arbitary::size_hint::recursion_guard` helper
function][recursion_guard] for guarding against infinite recursion in
`size_hint` implementations for recursive types.
### Changed
* The `Arbitrary::size_hint` signature now takes a `depth: usize`
parameter. This should be passed along unmodified to any nested calls of other
`size_hint` methods. If you're implementing `size_hint` for a recursive type
(like a linked list or tree) or a generic type with type parameters, you
should use [the new `arbitrary::size_hint::recursion_guard` helper
function][recursion_guard].
### Fixed
* Fixed infinite recursion in generated `size_hint` implementations
from `#[derive(Arbitrary)]` for recursive types.
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## 0.3.2
Released 2020-01-16.
### Changed
* Updated the custom derive's dependencies.
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## 0.3.2
Released 2020-01-15.
### Fixed
* Fixed an over-eager assertion condition in `Unstructured::int_in_range` that
would incorrectly trigger when given valid ranges of length one.
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## 0.3.1
Released 2020-01-14.
### Fixed
* Fixed some links and version numbers in README.
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## 0.3.0
Released 2020-01-14.
### Added
* Added the `"derive"` cargo feature, to enable `#[derive(Arbitrary)]` for
custom types. Enabling this feature re-exports functionality from the
`derive_arbitrary` crate.
* The custom derive for `Arbitrary` implements the shrink method for you now.
* All implementations of `Arbitrary` for `std` types implement shrinking now.
* Added the `Arbitrary::arbitrary_take_rest` method allows an `Arbitrary`
implementation to consume all of the rest of the remaining raw input. It has a
default implementation that forwards to `Arbitrary::arbitrary` and the custom
derive creates a smart implementation for your custom types.
* Added the `Arbitrary::size_hint` method for hinting how many raw bytes an
implementation needs to construct itself. This has a default implementation,
but the custom derive creates a smart implementation for your custom types.
* Added the `Unstructured::choose` method to choose one thing among a set of
choices.
* Added the `Unstructured::arbitrary_len` method to get an arbitrary length for
a collection of some arbitrary type.
* Added the `Unstructured::arbitrary_iter` method to create an iterator of
arbitrary instance of some type.
### Changed
* The `Arbitrary` trait was simplified a bit.
* `Unstructured` is a concrete type now, not a trait.
* Switched to Rust 2018 edition.
### Removed
* `RingBuffer` and `FiniteBuffer` are removed. Use `Unstructured` instead.
### Fixed
* Better `Arbitrary` implementation for `char`.
* Better `Arbitrary` implementation for `String`.
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## 0.2.0
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## 0.1.0