Function cvt

crates/common/src/crt_fd.rs:40–47

(ret: I)

#[inline]
fn cvt<I: num_traits::PrimInt>(ret: I) -> io::Result<I> {
    if ret < I::zero() {
        // CRT functions set errno, not GetLastError(), so use errno_io_error
        Err(crate::os::errno_io_error())
    } else {
        Ok(ret)
    }
}

fn cvt_fd(ret: Raw) -> io::Result<Owned> {
    cvt(ret).map(|fd| unsafe { Owned::from_raw(fd) })