dequeue for PriorityQueue should return Key-Value Pair not just Key

[micampbell]

Generally, the dequeue operation is to retrieve the value in a path-planning tree search. As currently implemented, one needs to call peek() to get to the "best" value (best is lowest or highest depending on direction), followed by dequeue!() to remove it. This is cumbersome and inefficient (two calls to get "best").
make dequeue! return the same as peek

[hdavid16]

There is dequeue_pair! to do this. However, I do agree that it makes sense to just have dequeue! do this.

[micampbell]

I didn't know of dequeue_pair!. That solves it, but this semantic choice is antithetical to all other programming languages.

[hdavid16]

I totally agree with you! I would recommend keeping this issue open since this syntax is not ideal for users.

[micampbell]

well, if you think it isn't too late to change....re-opened

[hdavid16]

It looks like #479 removes these and replaces them with popfirst!, which behaves as dequeue_pair!. This is to conform with Julia base.