20/isin array

[chaburkland]

Closes#20

Checklist

• Object 1D
• Object 2D
• Dtype 1D unique
• Dtype 2D unique
• Dtype 1D non-unique
• Dtype 2D non-unique

[brandtbucher]

Oh boy. 🙂

I just went over this quickly during lunch. I've refrained from checking or commenting on anything except refcounts, to keep this focused.

I may have missed or falsely flagged some since I went through this so quickly. But I'm confident most of them are genuine leaks.

[chaburkland]

Thanks @brandtbucher . These comments make me realize that my understanding of Python's object reference management is virtually non-existent. I'm thinking that it would be really helpful to meet with you to talk about it since I want to understand the core design of it, so that I can intuit where (and why) these leaks are happening myself