// Copyright 2016 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. use std::mem; // Univariant C-like enum #[repr(i32)] enum Univariant { X = 17 } #[repr(u16)] enum UnivariantWithoutDescr { Y } pub fn main() { { assert_eq!(4, mem::size_of::()); assert_eq!(17, Univariant::X as i32); let enums: &[Univariant] = &[Univariant::X, Univariant::X, Univariant::X]; let ints: &[i32] = unsafe { mem::transmute(enums) }; // check it has the same memory layout as i32 assert_eq!(&[17, 17, 17], ints); } { assert_eq!(2, mem::size_of::()); let descr = UnivariantWithoutDescr::Y as u16; let enums: &[UnivariantWithoutDescr] = &[UnivariantWithoutDescr::Y, UnivariantWithoutDescr::Y, UnivariantWithoutDescr::Y]; let ints: &[u16] = unsafe { mem::transmute(enums) }; // check it has the same memory layout as u16 assert_eq!(&[descr, descr, descr], ints); } }