Fast implementation of data structures, including a key-value store,
stack, and queue. Environments are commonly used as key-value stores
in R, but every time a new key is used, it is added to R's global
symbol table, causing a small amount of memory leakage. This can be
problematic in cases where many different keys are used. Fastmap
avoids this memory leak issue by implementing the map using data
structures in C++.

Homepage:
https://CRAN.R-project.org/package=fastmap
