Meta programming challenge

test.rb

class Class
  def reader(*names)
    names.each do |name|
      module_eval <<~CODE
        def #{name}
          @#{name}
        end
      CODE
    end
  end
end

class A
  def initialize
    @a = :a
    @b = :b
  end

  private

  attr_reader :a
  reader :b
end

p A.new.a # => test.rb:25:in `<main>': private method `a' called for #<A:0x00007fb5e90b42e8 @a=:a, @b=:b> (NoMethodError)
p A.new.b # => :b

__END__
How can I achieve, that my newly defined reader methods are also private. 
I could not figure out how to detect the private block or which API to use,
so that the newly defined methods are private by default.

This is the only way I could find to make it work:

class Class
  def reader(*names, binding)
    names.each do |name|
      eval <<~CODE, binding
        def #{name}
          @#{name}
        end
      CODE
    end
  end
end

class A
  def initialize
    @a = :a 
    @b = :b
  end

  private

  attr_reader :a
  reader :b, binding
end

or, using the bindings Gem this can be simplified to

require 'bindings'

class Class
  def reader(*names, binding = Binding.of_caller(1))
    names.each do |name|
      eval <<~CODE, binding
        def #{name}
          @#{name}
        end
      CODE
    end
  end
end

class A
  def initialize
    @a = :a 
    @b = :b
  end

  private

  attr_reader :a
  reader :b
end

class Class
  def reader(&block)
    names = Array(block.call)
    names.each do |name|
      eval <<~CODE, block.binding
        def #{name}
          @#{name}
        end
      CODE
    end
  end
end

class A
  def initialize
    @a = :a 
    @b = :b
  end

  private

  attr_reader :a
  reader { :b }
end