diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs index 6579b6887aaae..314cbb45d49e2 100644 --- a/library/std/src/io/mod.rs +++ b/library/std/src/io/mod.rs @@ -2989,11 +2989,11 @@ impl Read for Take { return Ok(()); } - if self.limit <= buf.capacity() as u64 { - // if we just use an as cast to convert, limit may wrap around on a 32 bit target - let limit = cmp::min(self.limit, usize::MAX as u64) as usize; + if self.limit < buf.capacity() as u64 { + // The condition above guarantees that `self.limit` fits in `usize`. + let limit = self.limit as usize; - let extra_init = cmp::min(limit as usize, buf.init_ref().len()); + let extra_init = cmp::min(limit, buf.init_ref().len()); // SAFETY: no uninit data is written to ibuf let ibuf = unsafe { &mut buf.as_mut()[..limit] };