rspec/rspec-expectations — pull request #641 by myronmarston (2014-08-28 01:12:53+00:00)
Title: Work around bug in 1.8.7's `Method#to_proc`.

I considered keeping the `Method#to_proc` implementation
for other rubies (1.9+), assuming it would be faster,
but benchmarks reveal it is in fact _slower_.

This fixes the failure @samphippen has been running into in rspec/rspec-mocks#751.