Minor pyi generator refactor while working on caching task
Minor pyi generator refactor while working on caching task

Summary:
Minor refactor.
using namespace std removed;
temp vars removed;
auto* explicitly specified;
code cleanup

Reviewed By: junzh0u

Differential Revision: D38394648

fbshipit-source-id: 2443817c7b372bcf9c0846e9e958ac4192d7298b

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