std: Re-enable at_exit()

The new semantics of this function are that the callbacks are run when the *main
thread* exits, not when all threads have exited. This implies that other threads
may still be running when the `at_exit` callbacks are invoked and users need to
be prepared for this situation.

Users in the standard library have been audited in accordance to these new rules
as well.

Closes #20012

1 files changed, 3 insertions, 5 deletions

diff --git a/src/libstd/sys/windows/tty.rs b/src/libstd/sys/windows/tty.rs
index 99292b3b44b..607bb05f54f 100644
--- a/src/libstd/sys/windows/tty.rs
+++ b/src/libstd/sys/windows/tty.rs
@@ -26,7 +26,6 @@
 //! to working in raw UTF-16, with such a wrapper around it.
 
 use super::c::{ReadConsoleW, WriteConsoleW, GetConsoleMode, SetConsoleMode};
-use super::c::{ERROR_ILLEGAL_CHARACTER};
 use super::c::{ENABLE_ECHO_INPUT, ENABLE_EXTENDED_FLAGS};
 use super::c::{ENABLE_INSERT_MODE, ENABLE_LINE_INPUT};
 use super::c::{ENABLE_PROCESSED_INPUT, ENABLE_QUICK_EDIT_MODE};
@@ -38,6 +37,8 @@ use prelude::*;
 use ptr;
 use str::from_utf8;
 
+use sys_common::unimpl;
+
 fn invalid_encoding() -> IoError {
     IoError {
         kind: io::InvalidInput,
@@ -149,11 +150,8 @@ impl TTY {
         // Make a CONSOLE_SCREEN_BUFFER_INFO
         // Call GetConsoleScreenBufferInfo
         // Maybe call GetLargestConsoleWindowSize instead?
-        Err(super::unimpl())
+        Err(unimpl())
     }
-
-    // Let us magically declare this as a TTY
-    pub fn isatty(&self) -> bool { true }
 }
 
 impl Drop for TTY {