What was the reason not to define == operator for Object class?

[voroninp]

I am curios why C# team decided not to define == operator for Object class which internally would simply call Object.Equals(left, righ).

Why did they prefer to emit ceq in this case?

[CyrusNajmabadi]

I am curios why C# team decided not to define == operator for Object class

The C# team does not own System.Object, the BCL does. However, the reasoning as i understand it is that an overloaded == is intended to be provided for types that provide value or value-like semantics. System.Object does not.

[voroninp]

Then why would they allow using == which implies this semantics... I mean - no operator defines in the hierarchy - no valid call.

[CyrusNajmabadi]

Then why would they allow using == which implies this semantics...

== does not imply those semantics by default. :)

== says: use the semantics provided. In this case, because there is no overload, it gets the default, which is reference equality, which is what was desired.

I mean - no operator defines in the hierarchy - no valid call.

No operator defined - default call.