Uniquify an array of hashes

Almost at the close of one of the cohort tasks I am working on and I need to uniquify an array of hashes. Many suggestions point to redefining #hash and #eql? for the hash instances before I put them in the array. And voila! there was anoitulos
and I qoute:
"Assuming your hashes are always single key-value pairs, this will work:

a.map {|h| h.to_a[0]}.uniq.map {|k,v| {k => v}}

Hash.to_a creates an array of key-value arrays, so the first map gets you:

[[:a, 1], [:a, 2], [:a, 1]]

uniq on Arrays does what you want, giving you:

[[:a, 1], [:a, 2]]

and then the second map puts them back together as hashes again.
"