std::ptr
pub unsafe extern "rust-intrinsic" fn write_bytes<T>( dst: *mut T, val: u8, count: usize)
Invokes memset on the specified pointer, setting count * size_of::<T>() bytes of memory starting at dst to val.
count * size_of::<T>()
dst
val
use std::ptr; let mut vec = vec![0; 4]; unsafe { let vec_ptr = vec.as_mut_ptr(); ptr::write_bytes(vec_ptr, b'a', 2); } assert_eq!(vec, [b'a', b'a', 0, 0]);Run