std::io::copy

Function generic_copy

Source 
pub(crate) fn generic_copy<R, W>(reader: &mut R, writer: &mut W) -> Result<u64>
where
    R: Read + ?Sized,
    W: Write + ?Sized,
Expand description

The userspace read-write-loop implementation of io::copy that is used when OS-specific specializations for copy offloading are not available or not applicable.