collections:
String::from_str
std_msc:
as_raw_fd
CString
c_str_to_bytes
core:
range
libc:
c_void, c_int, etc...
consts::os::extra::O_NONBLOCK
consts::os::posix01::F_SETFL
The ability to get a raw fd and set flags so that system calls can be used to read/write to sockets is especially useful if the core io lib wants to be used, and achieve non-blocking io on *nix systems.