bug with blank

[kostya]

i trying to add blank method, but this is not work for arrays:

crystal -e 'p ([] of Int32).blank?'
false

seems some bug with object inheritance.

diff --git a/src/nil.cr b/src/nil.cr
index a8586b3..4cfa225 100644
--- a/src/nil.cr
+++ b/src/nil.cr
@@ -58,4 +58,8 @@ struct Nil
   def not_nil!
     raise "Nil assertion failed"
   end
+
+  def blank?
+    true
+  end
 end
diff --git a/src/object.cr b/src/object.cr
index 6bfa53b..3cfc4a2 100644
--- a/src/object.cr
+++ b/src/object.cr
@@ -61,6 +61,18 @@ class Object
     self
   end

+  def blank?
+    if self.responds_to?(:empty?)
+      self.empty?
+    else
+      false
+    end
+  end
+
+  def present?
+    !self.blank?
+  end
+
   macro getter(name)
     def {{name.id}}
       @{{name.id}}

[asterite]

It seems the problem is actually with responds_to? not working well with generic classes:

class Foo(T)
  def bar
    true
  end
end

foo = Foo(Int32).new
puts foo.responds_to?(:bar) #=> false

As I side note, I was quite surprised that self.empty? compiled inside the if self.responds_to?(:empty), but it makes sense: self is a variable and its type is restricted inside the if.