| //! Smoke-test crate: pure integer functions, one with a seeded overflow bug. | |
| /// Correct: |a - b| without overflow. | |
| pub fn abs_diff(a: u32, b: u32) -> u32 { | |
| if a >= b { a - b } else { b - a } | |
| } | |
| /// Correct: saturating add via a wider type. | |
| pub fn sat_add_u8(a: u8, b: u8) -> u8 { | |
| let s = (a as u16) + (b as u16); | |
| if s > 255 { 255 } else { s as u8 } | |
| } | |
| /// Greatest common divisor (Euclid). | |
| pub fn gcd(a: u32, b: u32) -> u32 { | |
| let mut x = a; | |
| let mut y = b; | |
| while y != 0 { | |
| let t = x % y; | |
| x = y; | |
| y = t; | |
| } | |
| x | |
| } | |
| /// BUG (seeded): intended `floor((a + b) / 2)`, but `a + b` overflows u32 for large inputs | |
| /// (panics in debug, wraps in release). Correct form: `a / 2 + b / 2 + (a & b & 1)`. | |
| pub fn avg_buggy(a: u32, b: u32) -> u32 { | |
| (a + b) / 2 | |
| } | |