I've personally found heaptrack[1] pretty good for this task, very straightforward to use and the info is detailed enough. Though, it'll only tell you where they are happening (e.j. allocation rate for Box::new), but not exactly what type they are given that info isn't available at runtime. Usually that kind of thing would be reserved to GC-based languages where they keep track of counts for each object.

1: https://github.com/kde/heaptrack