scala/scala — pull request #2444 by paulp (2013-04-24 19:28:53+00:00)
Title: SI-6943 warn on value class miscomparison.

There's a very dangerous situation running around when you
combine universal equality with value classes:

// All over your code
val x = "abc"
if (x == "abc") ...

// Hey let's make x a value class
val x = new ValueClass("abc")
// Uh-oh

There was until now no warning when comparing a value class
with something else. Now there is.