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
• try-specialize
• coe-rs
• downcast-rs
• syllogism
• 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.