Concatenate two strings if not nil

concatenate_non_nil_strings.rb

class String
  def &(value = nil, default = "")
    value ? self + value.to_s : default.to_s
  end
end

# Mostly for consistency; not terribly useful
class NilClass
  def &(value = nil, default = "")
    default.to_s
  end
end

# Usage Examples
"word" & " with suffix"      # "word with suffix"
"word" & nil                 # ""
"word".&(nil,"nothing")      # "nothing"

# The intent behind this was for generating ImageMagick geometry strings
# See http://www.imagemagick.org/script/command-line-processing.php#geometry

# Assume a hash of arguments called @args:
width = args[:width]      # optional
height = args[:height]    # optional
geo = ("" & width) + ("x" & height)

# width = nil, height = nil, geo = ""
# width = 100, height = nil, geo = "100"
# width = nil, height = 100, geo = "x100"
# width = nil, height = 100, geo = "100x100"