Overview

ModNum is a highly ergonomic modular arithmetic struct intended for no_std use.

ModNum objects represent a value modulo m. The value and modulo can be of any primitive integer type. Arithmetic operators include +, - (both unary and binary), *, pow(), and ==. Additional capabilities include computing multiplicative inverses and solving modular equations.

ModNum was originally developed to facilitate bidirectional navigation through fixed-size arrays at arbitrary starting points. This is facilitated by a double-ended iterator that traverses the entire ring starting at any desired value.

Note that ModNum is not designed to work with arbitrary-length integers, as it requires its integer type to implement the Copy trait.

Updates

• 0.2: Added modular exponentiation and inverse.
• 0.3: Added division and modular exponentiation with negative exponents.
• 0.4:
  • Added ModNum as a right-hand side option for arithmetic operators.
  • Implemented Display for ModNum objects.
• 0.5:
  • Implemented the num::Saturating trait.
• 0.6:
  • Learned that num::Saturating is deprecated.
  • Removed num::Saturating implementation.
  • Replaced by implementing num::traits::SaturatingAdd and num::traits::SaturatingSub instead.