[rustc.git] / src / test / ui / transmutability / unions / should_permit_intersecting_if_validity_is_assumed.rs

// check-pass
//! If validity is assumed, there need only be one matching bit-pattern between
//! the source and destination types.

#![crate_type = "lib"]
#![feature(transmutability)]
#![allow(dead_code, incomplete_features, non_camel_case_types)]

mod assert {
    use std::mem::{Assume, BikeshedIntrinsicFrom};
    pub struct Context;

    pub fn is_maybe_transmutable<Src, Dst>()
    where
        Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY.and(Assume::VALIDITY) }>
    {}
}

#[derive(Clone, Copy)] #[repr(u8)] enum Ox00 { V = 0x00 }
#[derive(Clone, Copy)] #[repr(u8)] enum Ox7F { V = 0x7F }
#[derive(Clone, Copy)] #[repr(u8)] enum OxFF { V = 0xFF }

fn test() {
    #[repr(C)]
    union A {
        a: Ox00,
        b: Ox7F,
    }

    #[repr(C)]
    union B {
        a: Ox7F,
        b: OxFF,
    }

    assert::is_maybe_transmutable::<A, B>();
    assert::is_maybe_transmutable::<B, A>();
}
Commit	Line	Data
064997fb FG	1	// check-pass
	2	//! If validity is assumed, there need only be one matching bit-pattern between
	3	//! the source and destination types.
	4
	5	#![crate_type = "lib"]
	6	#![feature(transmutability)]
	7	#![allow(dead_code, incomplete_features, non_camel_case_types)]
	8
	9	mod assert {
f2b60f7d	10	use std::mem::{Assume, BikeshedIntrinsicFrom};
064997fb FG	11	pub struct Context;
	12
	13	pub fn is_maybe_transmutable<Src, Dst>()
	14	where
f2b60f7d	15	Dst: BikeshedIntrinsicFrom<Src, Context, { Assume::SAFETY.and(Assume::VALIDITY) }>
064997fb FG	16	{}
	17	}
	18
	19	#[derive(Clone, Copy)] #[repr(u8)] enum Ox00 { V = 0x00 }
	20	#[derive(Clone, Copy)] #[repr(u8)] enum Ox7F { V = 0x7F }
	21	#[derive(Clone, Copy)] #[repr(u8)] enum OxFF { V = 0xFF }
	22
	23	fn test() {
	24	#[repr(C)]
	25	union A {
	26	a: Ox00,
	27	b: Ox7F,
	28	}
	29
	30	#[repr(C)]
	31	union B {
	32	a: Ox7F,
	33	b: OxFF,
	34	}
	35
	36	assert::is_maybe_transmutable::<A, B>();
	37	assert::is_maybe_transmutable::<B, A>();
	38	}