rust/tests/ui/consts/const-int-arithmetic-overflow.rs
2023-01-11 09:32:08 +00:00

26 lines
773 B
Rust

// run-pass
// compile-flags: -O
// Make sure arithmetic unary/binary ops actually return the right result, even when overflowing.
// We have to put them in `const fn` and turn on optimizations to avoid overflow checks.
const fn add(x: i8, y: i8) -> i8 { x+y }
const fn sub(x: i8, y: i8) -> i8 { x-y }
const fn mul(x: i8, y: i8) -> i8 { x*y }
// div and rem are always checked, so we cannot test their result in case of overflow.
const fn neg(x: i8) -> i8 { -x }
fn main() {
const ADD_OFLOW: i8 = add(100, 100);
assert_eq!(ADD_OFLOW, -56);
const SUB_OFLOW: i8 = sub(100, -100);
assert_eq!(SUB_OFLOW, -56);
const MUL_OFLOW: i8 = mul(-100, -2);
assert_eq!(MUL_OFLOW, -56);
const NEG_OFLOW: i8 = neg(-128);
assert_eq!(NEG_OFLOW, -128);
}