[rustc.git] / src / test / ui / consts / const-eval / nrvo.rs

// run-pass

// When the NRVO is applied, the return place (`_0`) gets treated like a normal local. For example,
// its address may be taken and it may be written to indirectly. Ensure that MIRI can handle this.

#![feature(const_mut_refs)]

#[inline(never)] // Try to ensure that MIR optimizations don't optimize this away.
const fn init(buf: &mut [u8; 1024]) {
    buf[33] = 3;
    buf[444] = 4;
}

const fn nrvo() -> [u8; 1024] {
    let mut buf = [0; 1024];
    init(&mut buf);
    buf
}

const BUF: [u8; 1024] = nrvo();

fn main() {
    assert_eq!(BUF[33], 3);
    assert_eq!(BUF[19], 0);
    assert_eq!(BUF[444], 4);
}
Commit	Line	Data
f9f354fc XL	1	// run-pass
	2
	3	// When the NRVO is applied, the return place (`_0`) gets treated like a normal local. For example,
	4	// its address may be taken and it may be written to indirectly. Ensure that MIRI can handle this.
	5
	6	#![feature(const_mut_refs)]
	7
	8	#[inline(never)] // Try to ensure that MIR optimizations don't optimize this away.
	9	const fn init(buf: &mut [u8; 1024]) {
	10	buf[33] = 3;
	11	buf[444] = 4;
	12	}
	13
	14	const fn nrvo() -> [u8; 1024] {
	15	let mut buf = [0; 1024];
	16	init(&mut buf);
	17	buf
	18	}
	19
	20	const BUF: [u8; 1024] = nrvo();
	21
	22	fn main() {
	23	assert_eq!(BUF[33], 3);
	24	assert_eq!(BUF[19], 0);
	25	assert_eq!(BUF[444], 4);
	26	}