I want to suggest Hash#count be defined such that it counts hash
values. A it stands (using Enumerable#count) it only can ever return 0
or 1.

Current:

  {:a=>1,:b=2,:c=>1}.count([:a,1]) #=> 1
  {:x=>1,:b=2,:c=>1}.count([:a,1]) #=> 0
  {:a=>1,:b=2,:c=>1}.count(1)      #=> 0

Proposed:

  {:a=>1,:b=2,:c=>1}.count(1) #=> 2
  {:x=>1,:b=2,:c=>1}.count(1) #=> 2

It would be more useful that way. And, in the same vain, a #has_pair?
seems like an obvious addition.