#integer #big-int #big-integer #numbers

smallbigint

Big integer types that have a small on-stack representation for small values. Uses num-bigint internally.

10 releases (3 stable)

1.1.0 Dec 13, 2020
0.7.0 Apr 5, 2020
0.6.0 Mar 29, 2020

#1694 in Data structures

MIT/Apache

67KB
1.5K SLoC

Smallbigint

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Two types, Uint and Int, like smallvec for big integers. Anything that fits in 32 bits stays on the stack. Numbers that don't fit are stored in a Box<num_bigint::BigUint> / Box<num_bigint::BigInt>.

On 64-bit architectures, by default we use unsafe to compress the types to 8 bytes, exploiting pointer alignment. This behavior is triggered by the unsafe-opt feature, which is enabled by default.

Implemented traits

Most important numeric traits have been implemented. Here are some that aren't yet; pull requests are welcome!

  • Bit operations
  • num_traits::Num, num_traits::Signed, num_traits::Unsigned, num_integer::Integer, num_integer::Roots, std::iter::Product, std::iter::Sum, num_traits::pow::Pow
  • Other methods implemented directly on BigInt, BigUint
  • Implement num_bigint::{ToBigInt, ToBigUint}

License

This project is licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Dependencies

~550KB
~12K SLoC