ruby - Why does this semantically identical class cause an undefined method 'new' error? -

why following code error:

class complex     def initialize(real, imaginary)         @imaginary = imaginary         @real = real     end      end  c = complex.new(5,3)

complex.rb:8:in <main>': undefined methodnew' complex:class (nomethoderror)

but semantically identical program below not:

class wat     def initialize(a, b)         @a =         @b = b     end      end  c = wat.new(5,3)

because complex exists, , built in different way, e.g.,

complex(2, 3)

when re-open class (not defining own) operate under existing class's constraints.

new removed somewhere around 1.9 iirc.

UIO