Macro cjdns_admin::cjdns_invoke

macro_rules! cjdns_invoke {
    ($cjdns:expr, $fn_name:literal) => { ... };
    ($cjdns:expr, $fn_name:literal, $( $arg_name:literal = $arg_value:expr ),*) => { ... };
}

Helper macro to easily invoke remote function with arguments.

Examples:

let res = cjdns_invoke!(conn, "FuncName").await?;
let res = cjdns_invoke!(conn, "FuncName", "arg1" = 42, "arg2" = "foobar").await?;