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Core traits and error types of the [rand] library, plus tools for implementing
This version of `rand_core` is a compatibility shim around version 0.3.
This crate is intended for use when implementing the core trait, `RngCore`; it
defines the core traits to be implemented as well as several small functions to
aid in their implementation and types required for error handling.
The main [rand] crate re-exports most items defined in this crate, along with
tools to convert the integer samples generated by `RngCore` to many different
applications (including sampling from restricted ranges, conversion to floating
point, list permutations and secure initialisation of RNGs). Most users should
prefer to use the main [rand] crate.
The `rand_core` crate provides:
- base random number generator traits
- error-reporting types
- functionality to aid implementation of RNGs
The traits and error types are also available via `rand`.
## Crate Features
`rand_core` supports `no_std` and `alloc`-only configurations, as well as full
`std` functionality. The differences between `no_std` and full `std` are small,
comprising `RngCore` support for `Box<R>` types where `R: RngCore`, as well as
extensions to the `Error` type's functionality.
Due to [rust-lang/cargo#1596](https://github.com/rust-lang/cargo/issues/1596),
`rand_core` is built without `std` support by default. Since features are
unioned across the whole dependency tree, any crate using `rand` with its
default features will also enable `std` support in `rand_core`.
The `serde1` feature can be used to derive `Serialize` and `Deserialize` for RNG
implementations that use the `BlockRng` or `BlockRng64` wrappers.
`rand_core` is distributed under the terms of both the MIT license and the
Apache License (Version 2.0).
See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT) for details.