// Aligned to two bytes const DATA: [u16; 2] = [u16::from_ne_bytes([0x01, 0x23]), u16::from_ne_bytes([0x45, 0x67])]; const fn unaligned_ptr() -> *const u16 { // Since DATA.as_ptr() is aligned to two bytes, adding 1 byte to that produces an unaligned *const u16 unsafe { (DATA.as_ptr() as *const u8).add(1) as *const u16 } } #[test] fn read() { use core::ptr; const FOO: i32 = unsafe { ptr::read(&42 as *const i32) }; assert_eq!(FOO, 42); const ALIGNED: i32 = unsafe { ptr::read_unaligned(&42 as *const i32) }; assert_eq!(ALIGNED, 42); const UNALIGNED_PTR: *const u16 = unaligned_ptr(); const UNALIGNED: u16 = unsafe { ptr::read_unaligned(UNALIGNED_PTR) }; assert_eq!(UNALIGNED, u16::from_ne_bytes([0x23, 0x45])); } #[test] fn const_ptr_read() { const FOO: i32 = unsafe { (&42 as *const i32).read() }; assert_eq!(FOO, 42); const ALIGNED: i32 = unsafe { (&42 as *const i32).read_unaligned() }; assert_eq!(ALIGNED, 42); const UNALIGNED_PTR: *const u16 = unaligned_ptr(); const UNALIGNED: u16 = unsafe { UNALIGNED_PTR.read_unaligned() }; assert_eq!(UNALIGNED, u16::from_ne_bytes([0x23, 0x45])); } #[test] fn mut_ptr_read() { const FOO: i32 = unsafe { (&42 as *const i32 as *mut i32).read() }; assert_eq!(FOO, 42); const ALIGNED: i32 = unsafe { (&42 as *const i32 as *mut i32).read_unaligned() }; assert_eq!(ALIGNED, 42); const UNALIGNED_PTR: *mut u16 = unaligned_ptr() as *mut u16; const UNALIGNED: u16 = unsafe { UNALIGNED_PTR.read_unaligned() }; assert_eq!(UNALIGNED, u16::from_ne_bytes([0x23, 0x45])); } //#[test] //fn write() { // use core::ptr; // // const fn write_aligned() -> i32 { // let mut res = 0; // unsafe { // ptr::write(&mut res as *mut _, 42); // } // res // } // const ALIGNED: i32 = write_aligned(); // assert_eq!(ALIGNED, 42); // // const fn write_unaligned() -> [u16; 2] { // let mut two_aligned = [0u16; 2]; // unsafe { // let unaligned_ptr = (two_aligned.as_mut_ptr() as *mut u8).add(1) as *mut u16; // ptr::write_unaligned(unaligned_ptr, u16::from_ne_bytes([0x23, 0x45])); // } // two_aligned // } // const UNALIGNED: [u16; 2] = write_unaligned(); // assert_eq!(UNALIGNED, [u16::from_ne_bytes([0x00, 0x23]), u16::from_ne_bytes([0x45, 0x00])]); //} //#[test] //fn mut_ptr_write() { // const fn aligned() -> i32 { // let mut res = 0; // unsafe { // (&mut res as *mut i32).write(42); // } // res // } // const ALIGNED: i32 = aligned(); // assert_eq!(ALIGNED, 42); // // const fn write_unaligned() -> [u16; 2] { // let mut two_aligned = [0u16; 2]; // unsafe { // let unaligned_ptr = (two_aligned.as_mut_ptr() as *mut u8).add(1) as *mut u16; // unaligned_ptr.write_unaligned(u16::from_ne_bytes([0x23, 0x45])); // } // two_aligned // } // const UNALIGNED: [u16; 2] = write_unaligned(); // assert_eq!(UNALIGNED, [u16::from_ne_bytes([0x00, 0x23]), u16::from_ne_bytes([0x45, 0x00])]); //}