Signed and unsigned integers

A signed int (one that can have positive or negative values) is defined like this:

let sint = 10i32; 

An unsigned int has a u instead of i in the definition:

let usint = 10u32; 

Again, these are number literals, and the same declaration can be made via types:

let sint: i32 = 10; 

Both signed and unsigned int values can be 8, 16, 32, or 64-bits long.