vec_ext.rs (871B)
1 // Copyright 2019 The Servo Project Developers. See the COPYRIGHT 2 // file at the top-level directory of this distribution and at 3 // http://rust-lang.org/COPYRIGHT. 4 // 5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or 6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license 7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your 8 // option. This file may not be copied, modified, or distributed 9 // except according to those terms. 10 11 pub trait VecExt { 12 type Item; 13 unsafe fn set_end_ptr(&mut self, end: *const Self::Item); 14 } 15 16 impl<T> VecExt for Vec<T> { 17 type Item = T; 18 unsafe fn set_end_ptr(&mut self, end: *const T) { 19 assert!(end as usize >= self.as_ptr() as usize); 20 let new_len = end as usize - self.as_ptr() as usize; 21 assert!(new_len <= self.capacity()); 22 self.set_len(new_len); 23 } 24 }