Function nanomsg_sys::nn_setsockopt

pub unsafe extern "C" fn nn_setsockopt(
    socket: c_int, 
    level: c_int, 
    option: c_int, 
    optval: *const c_void, 
    optvallen: size_t
) -> c_int

"Sets the value of the option. The level argument specifies the protocol level at which the option resides. For generic socket-level options use NN_SOL_SOCKET level. For socket-type-specific options use socket type for level argument (e.g. NN_SUB). For transport-specific options use ID of the transport as the level argument (e.g. NN_TCP).

The new value is pointed to by optval argument. Size of the option is specified by the optvallen argument."

http://nanomsg.org/v0.4/nn_setsockopt.3.html