Any interest in a Numeric#to_format(:format) ?

I've got some basic code working for creating custom Numeric formats,
which can be used with a Numeric#to_format(:format) method (similar to
Time#to_s(:format).)

Here's an example -- some custom formats, which can be added to the
environment:

Numeric::FORMATS = {
  :dollars => {:precision => 2, :delimited => true, :unit_prefix =>
'$'},
  :cents_to_dollars => lambda { |cents| (cents /
100.0).to_format(:dollars) },
  :fluid_ounces => {:precision => 1, :delimited => true, :unit_suffix
=> ' fl oz'},
  :sku => {:prefix => '[', :unit_prefix => 'SKU', :suffix => ']'}
}

And their use:

2101.50.to_format(:dollars) # => "$2,101.50"
-2101.50.to_format(:dollars) # => "-$2,101.50"
210150.to_format(:cents_to_dollars) # => "$2,101.50"
16.to_format(:fluid_ounces) # => "16.0 fl oz"
912354678.to_format(:sku) # => [SKU912354678]

This allows measurements to be outputted with their units in a
consistent format across the app (as opposed to just in ActionView,
with the current numeric helpers.)

Would there be any interest in including something like this in the
core?

Thanks,
Geoff