rollup merge of #23630: nrc/coerce-tidy

See notes on the first commit

Closes #18601

r? @nikomatsakis

cc @eddyb

5 files changed, 7 insertions, 4 deletions

diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 90eca6168f2..cca6bb747d4 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -135,6 +135,8 @@
 #![feature(no_std)]
 #![no_std]
 
+#![allow(trivial_casts)]
+#![allow(trivial_numeric_casts)]
 #![deny(missing_docs)]
 
 #[cfg(test)] extern crate test;
diff --git a/src/libstd/old_io/stdio.rs b/src/libstd/old_io/stdio.rs
index fd3fae641e2..90d27084911 100644
--- a/src/libstd/old_io/stdio.rs
+++ b/src/libstd/old_io/stdio.rs
@@ -337,10 +337,10 @@ pub fn set_stderr(_stderr: Box<Writer + Send>) -> Option<Box<Writer + Send>> {
 //      })
 //  })
 fn with_task_stdout<F>(f: F) where F: FnOnce(&mut Writer) -> IoResult<()> {
-    let mut my_stdout = LOCAL_STDOUT.with(|slot| {
+    let mut my_stdout: Box<Writer + Send> = LOCAL_STDOUT.with(|slot| {
         slot.borrow_mut().take()
     }).unwrap_or_else(|| {
-        box stdout() as Box<Writer + Send>
+        box stdout()
     });
     let result = f(&mut *my_stdout);
     let mut var = Some(my_stdout);
diff --git a/src/libstd/rt/mod.rs b/src/libstd/rt/mod.rs
index 43aa4155629..497076cc6ac 100644
--- a/src/libstd/rt/mod.rs
+++ b/src/libstd/rt/mod.rs
@@ -68,7 +68,7 @@ fn lang_start(main: *const u8, argc: int, argv: *const *const u8) -> int {
     use thread::Thread;
 
     let something_around_the_top_of_the_stack = 1;
-    let addr = &something_around_the_top_of_the_stack as *const int;
+    let addr = &something_around_the_top_of_the_stack as *const _ as *const int;
     let my_stack_top = addr as uint;
 
     // FIXME #11359 we just assume that this thread has a stack of a
diff --git a/src/libstd/sys/windows/os.rs b/src/libstd/sys/windows/os.rs
index 83d06371734..167db1e8ac2 100644
--- a/src/libstd/sys/windows/os.rs
+++ b/src/libstd/sys/windows/os.rs
@@ -109,7 +109,7 @@ impl Iterator for Env {
             if *self.cur == 0 { return None }
             let p = &*self.cur;
             let mut len = 0;
-            while *(p as *const _).offset(len) != 0 {
+            while *(p as *const u16).offset(len) != 0 {
                 len += 1;
             }
             let p = p as *const u16;
diff --git a/src/libstd/thread/local.rs b/src/libstd/thread/local.rs
index 1bf1b09681c..a2b824bb016 100644
--- a/src/libstd/thread/local.rs
+++ b/src/libstd/thread/local.rs
@@ -176,6 +176,7 @@ macro_rules! __thread_local_inner {
             }
         };
 
+        #[allow(trivial_casts)]
         #[cfg(any(not(any(target_os = "macos", target_os = "linux")), target_arch = "aarch64"))]
         const _INIT: ::std::thread::__local::__impl::KeyInner<$t> = {
             ::std::thread::__local::__impl::KeyInner {