Function SCIPsetSetLongintParam 

pub unsafe extern "C" fn SCIPsetSetLongintParam(
    set: *mut SCIP_SET,
    messagehdlr: *mut SCIP_MESSAGEHDLR,
    name: *const c_char,
    value: c_longlong,
) -> SCIP_RETCODE

changes the value of an existing SCIP_Longint parameter