This is a Work In Progress. Issues and Pull Requests Welcome!

You can use this crate to get information on how your code uses SmallVecs. What it does is writing a log of all SmallVec constructions, resizings and destructions by array size.

Each line in the log is composed of <id>;<item size>;<array size>;[+/-];<previous capacity>;<new capacity>, where the first item is the size of the array's item type, the second is the array size (we can use this to distinguish various smallvec uses within one application), the third is + for a new allocation, - for a deallocation and space on resize, and the fourth and fifth are the capacity before and after the operation (if any).

For example, creating a smallvec of u8, extending and dropping it may create the following log (here annotated for clarity):

0;1;1;+;;1      # create
0;1;1; ;1;100   # extend (allocate+deallocate)
0;1;1;-;100     # drop

In your Cargo.toml, replace your smallvec dependency with smallvectune. Then in your lib.rs (or main.rs), replace extern crate smallvec; with extern crate smallvectune as smallvec;.

Calling your code, you'll have to set the SMALLVECTUNE_OUT environment variable to a valid path to write to. This is where the log will be written.

This is under Apache/2 or MIT license, per your choice. All contributions are also given under the same license.