Macro rb_tree::rbqueue_c_new

macro_rules! rbqueue_c_new {
    ($cmp:expr) => { ... };
}

Allows the creation of a queue using C-like comparison values. That is to say, cmp should return a value less than, equal to, or greater than 0 when l should be placed before, is equal to, or be placed after r respectively.

cmp should be a function that takes two values from the queue and returns an integer (i8) providing the information as above.

Example:

let mut q = rbqueue_c_new!(|l: &i64, r| (r - l));
q.insert(1);
q.insert(2);
q.insert(3);
assert_eq!(q.ordered(), [&3, &2, &1]);