Rollup merge of #127733 - GrigorenkoPV:don't-forget, r=Amanieu

Replace some `mem::forget`'s with `ManuallyDrop`

              > but I would like to see a larger effort to replace all uses of `mem::forget`.

_Originally posted by `@saethlin` in https://github.com/rust-lang/rust/issues/127584#issuecomment-2226087767_

So,
r? `@saethlin`

Sorry, I have finished writing all of this before I got your response.

1 files changed, 5 insertions, 9 deletions

diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
index 619f4e4121e..483697b8597 100644
--- a/library/std/src/sys/pal/unix/thread.rs
+++ b/library/std/src/sys/pal/unix/thread.rs
@@ -1,7 +1,7 @@
 use crate::cmp;
 use crate::ffi::CStr;
 use crate::io;
-use crate::mem;
+use crate::mem::{self, ManuallyDrop};
 use crate::num::NonZero;
 use crate::ptr;
 use crate::sys::{os, stack_overflow};
@@ -268,11 +268,9 @@ impl Thread {
     }
 
     pub fn join(self) {
-        unsafe {
-            let ret = libc::pthread_join(self.id, ptr::null_mut());
-            mem::forget(self);
-            assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret));
-        }
+        let id = self.into_id();
+        let ret = unsafe { libc::pthread_join(id, ptr::null_mut()) };
+        assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret));
     }
 
     pub fn id(&self) -> libc::pthread_t {
@@ -280,9 +278,7 @@ impl Thread {
     }
 
     pub fn into_id(self) -> libc::pthread_t {
-        let id = self.id;
-        mem::forget(self);
-        id
+        ManuallyDrop::new(self).id
     }
 }