In a few places in `std` there are casts from `usize` to `u32` or `i32` for Windows APIs which causes breakage on 64-bit. Some examples I have found so far: - [x] [Files/Pipes](https://github.com/rust-lang/rust/blob/6ffd7cd1664b70fed34861df3957ddee87ec9ad1/src/libstd/sys/windows/handle.rs#L69) (#31825) - [x] [Networking](https://github.com/rust-lang/rust/blob/6ffd7cd1664b70fed34861df3957ddee87ec9ad1/src/libstd/sys/windows/net.rs#L136) (#31858) - [x] [Rand](https://github.com/rust-lang/rust/blob/6ffd7cd1664b70fed34861df3957ddee87ec9ad1/src/libstd/sys/windows/rand.rs#L52) (rust-lang-nursery/rand#99, #31876) There may be more.