Converts RGB color values into equivalent hex codes in Ruby

rgb_to_hex.rb

# best solution
def rgb(r,g,b)
  "%.2X%.2X%.2X" % [r,g,b].map{|c| [[c,255].min,0].max}
end

# needs a more DRY way of handling single digit hex conversion
def rgb(r, g, b)
   [r,g,b].map{ |c| [[c,255].min,0].max > 16 ? [[c,255].min,0].max.to_s(16) : "0#{[[c,255].min,0].max.to_s(16)}"}.join.upcase
end

# needs a more clever way of handling upper and lower bounds
def rgb(r, g, b)
   [r,g,b].map{ |c| c < 255 ? c : 255}.map{ |c| c > 0 ? c : 0}.map{ |c|  c > 16 ? c.to_s(16) : "0#{c.to_s(16)}"}.join.upcase
end