From 56613f8c382351898f9267bac8e8324f118eb79d Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Thu, 20 Apr 2023 20:15:04 -0700 Subject: More `IS_ZST` in `library` I noticed that `post_inc_start` and `pre_dec_end` were doing this check in different ways https://github.com/rust-lang/rust/blob/d19b64fb54391b64ce99981577c67c93ac2a9ffa/library/core/src/slice/iter/macros.rs#L76-L93 so started making this PR, then added a few more I found since I was already making changes anyway. --- library/alloc/src/vec/drain.rs | 4 +--- library/alloc/src/vec/drain_filter.rs | 6 ++---- 2 files changed, 3 insertions(+), 7 deletions(-) (limited to 'library/alloc/src/vec') diff --git a/library/alloc/src/vec/drain.rs b/library/alloc/src/vec/drain.rs index 2b1a787cc54..45b03fb680b 100644 --- a/library/alloc/src/vec/drain.rs +++ b/library/alloc/src/vec/drain.rs @@ -112,9 +112,7 @@ impl<'a, T, A: Allocator> Drain<'a, T, A> { let unyielded_ptr = this.iter.as_slice().as_ptr(); // ZSTs have no identity, so we don't need to move them around. - let needs_move = mem::size_of::() != 0; - - if needs_move { + if !T::IS_ZST { let start_ptr = source_vec.as_mut_ptr().add(start); // memmove back unyielded elements diff --git a/library/alloc/src/vec/drain_filter.rs b/library/alloc/src/vec/drain_filter.rs index 8c03f1692d9..650f9213890 100644 --- a/library/alloc/src/vec/drain_filter.rs +++ b/library/alloc/src/vec/drain_filter.rs @@ -1,5 +1,5 @@ use crate::alloc::{Allocator, Global}; -use core::mem::{self, ManuallyDrop}; +use core::mem::{ManuallyDrop, SizedTypeProperties}; use core::ptr; use core::slice; @@ -96,9 +96,7 @@ where unsafe { // ZSTs have no identity, so we don't need to move them around. - let needs_move = mem::size_of::() != 0; - - if needs_move && this.idx < this.old_len && this.del > 0 { + if !T::IS_ZST && this.idx < this.old_len && this.del > 0 { let ptr = this.vec.as_mut_ptr(); let src = ptr.add(this.idx); let dst = src.sub(this.del); -- cgit 1.4.1-3-g733a5