Auto merge of #23832 - petrochenkov:usize, r=aturon

These constants are small and can fit even in `u8`, but semantically they have type `usize` because they denote sizes and are almost always used in `usize` context. The change of their type to `u32` during the integer audit led only to the large amount of `as usize` noise (see the second commit, which removes this noise).

This is a minor [breaking-change] to an unstable interface.

r? @aturon 

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/sys/unix/c.rs b/src/libstd/sys/unix/c.rs
index 2514d4bf4a3..5ae508e4610 100644
--- a/src/libstd/sys/unix/c.rs
+++ b/src/libstd/sys/unix/c.rs
@@ -194,12 +194,12 @@ mod select {
     #[repr(C)]
     pub struct fd_set {
         // FIXME: shouldn't this be a c_ulong?
-        fds_bits: [libc::uintptr_t; (FD_SETSIZE / usize::BITS as usize)]
+        fds_bits: [libc::uintptr_t; (FD_SETSIZE / usize::BITS)]
     }
 
     pub fn fd_set(set: &mut fd_set, fd: i32) {
         let fd = fd as usize;
-        set.fds_bits[fd / usize::BITS as usize] |= 1 << (fd % usize::BITS as usize);
+        set.fds_bits[fd / usize::BITS] |= 1 << (fd % usize::BITS);
     }
 }