Which methods an Any type should have?

Here under Any root of objects hierarchy is meant

Why there should be no hashCode, equals in Any (and entire Comparable as a type)

These methods look like a Java legacy, as they prohibit modifications, that make collections work different for different types. For instance, Map can be implemented via Set, if pair comparator compares only first elements (same with hashCode and equals). Instead of all this methods, their users must accept a Comparator and so on, where there may be a "default" that does language-specific things

Why there should be no equals?

equals semantics may be different:

• It may compare pointers
• It may compare values
• It may compare values in a special way ($-0\ne +0$)
  

There is also an issue with "pointers comparison", as single dispatch can't correctly handle all null/undefined cases

Should there be a toString?

Well, there are two issues with toString:

1. I am pretty sure that default toString signature is incorrect. Why is it this.toString(): String and not this.toString(sb: StringBuilder): void? First variant has extremely degraded performance, while second variant allows just making a stub
2. Why is it called toString? It should be called toDebugString. And should it be possible to override such method? That is probably a philosophical question, I would tend to answer "no", but who knows
   

Proposed Any type

class Any {
	final fn toDebugString(): String {
		let sb = new StringBuilder()
		this.toDebugString(sb)
		return sb.getString()
	}

	open fn toDebugString(sb: StringBuilder): Unit {
		Runtime.dump(this, sb)
	}
}

namespace Runtime {
	fn isSameReference(l: Any, r: Any): Boolean
	fn getSystemHashCode(a: Any): USize
}