rust-lang/rust — pull request #16204 by bkoropoff (2014-08-02 20:30:16+00:00)
Title: Make vec!() macro create a vector with precise capacity

This seemed like a small but obvious optimization. Feedback questions:

- Is the count_args!() macro a good fit for libstd? It seems like it might be generally useful for macro writers.
- I can add a few unit tests, but where should I put them?