# Specializer
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[](https://github.com/AldaronLau/specializer)
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[](https://crates.io/crates/specializer)
[](https://crates.io/crates/specializer)
[](https://crates.io/crates/specializer)
[](https://github.com/search?q=repo%3AAldaronLau%2Fspecializer+path%3A**%2FLICENSE*&type=code)
[](https://docs.rs/specializer/)
Limited safe specialization on stable Rust with builder-like pattern
Check out the [documentation] for examples.
### Features
- Functions to do a fallible cast to/from generics/concrete types
- Supports casting with `'static` types and borrowed types
- Sync/async builders for chaining type specialization
- No-std/no-alloc
- No unsafe
## MSRV
The current MSRV is Rust 1.85.
Any future MSRV updates will follow the [Ardaku MSRV guidelines].
## Alternatives
- [castaway](https://crates.io/crates/castaway)
- [try-specialize](https://crates.io/crates/try-specialize)
- [coe-rs](https://crates.io/crates/coe-rs)
- [downcast-rs](https://crates.io/crates/downcast-rs)
- [syllogism](https://crates.io/crates/syllogism)
- [identity\_cast](https://crates.io/crates/identity_cast)
## License
Copyright © 2025 The Specializer Contributors.
Licensed under any of
- Apache License, Version 2.0, ([LICENSE\_APACHE] or
<https://www.apache.org/licenses/LICENSE-2.0>)
- Boost Software License, Version 1.0, ([LICENSE\_BOOST] or
<https://www.boost.org/LICENSE_1_0.txt>)
- MIT License, ([LICENSE\_MIT] or <https://mit-license.org/>)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in the work by you, as defined in the Apache-2.0 license, shall be
licensed as described above, without any additional terms or conditions.
## Help
If you want help using or contributing to this library, feel free to send me an
email at <aldaronlau@gmail.com>.
[Ardaku MSRV guidelines]: https://github.com/ardaku/.github/blob/v1/profile/MSRV.md
[LICENSE\_APACHE]: https://github.com/AldaronLau/specializer/blob/v1/LICENSE_APACHE
[LICENSE\_BOOST]: https://github.com/AldaronLau/specializer/blob/v1/LICENSE_BOOST
[LICENSE\_MIT]: https://github.com/AldaronLau/specializer/blob/v1/LICENSE_MIT
[documentation]: https://docs.rs/specializer