mozilla/rust — pull request #8029 by emillon (2013-07-24 23:47:48+00:00)
Title: Check for comparisons to NaN in patterns

Hi,

As noted in #6804, a pattern that contains `NaN` will never match because `NaN != NaN`. This adds a warning for such a case. The first commit handles the basic case and the second one generalizes it to more complex patterns using `walk_pat`.