RotaryAdd: Cyclical arithemtic with unsigned integers

This crate provides 2 traits, RotaryAdd and CyccleAdd, with two simple methods to apply cyclical or modular addition and subtraction with three unsigned integer types, u8, u16 and u32. Unlike the default + and - operators, additions and subtractions never overflow.

RotaryAdd

This trait has addition and subtraction methods that act on the whole range of an unsigned integer, e.g. from 0 to 255 for u8 or from 0 to 65535 for u16. This example with an 8-bit unsigned integer illustrates the concept with the rotary_add and rotary_sub methods:

Addition:

let first_number: u8 = 255;
let second_number: u8 = 6;

let result = first_number.rotary_add(&second_number);
// yields 5. first_number + second_number would panic as the value would overflow

Subtraction

let first_number: u8 = 3;
let second_number: u8 = 6;
let result = first_number.rotary_sub(&second_number);
// yields 253. first_number - second_number would panic as the value would overflow

CycleAdd

This trait provides addition and subtraction methods that let you define a custom cyclic base.

These examples show the concept:

Addition:

let first_number: u8 = 22;
let second_number: u8 = 6;

let result = first_number.cycle_add(&second_number, 24);
// yields 4. We have to use u8 as a primitive data type, but

Subtraction

let first_number: u8 = 37;
let second_number: u8 = 78;
let result = first_number.cycle_sub(&second_number, 100);
// yields 59. first_number - second_number would panic as the value would overflow

Unlike the related Ring360 crate, this library only extends core unsigned integer types for use with cryptography and as a building block for other crates, e.g. converting characters first to u32 values and then shifting their values in one direction in the encoding stage and reversing the process in the decoding stage.

Dev notes

This is an alpha release.