On 7/1/2011 9:56 AM, Daniel Murphy wrote:
If I understand this correctly, you think the following code should be perfectly valid:class A { void func(uint x) in { assert(x< 10); } body {} } class B : A { void func(uint x) in { assert(x == 50); } body {} }
Yes.
If A.func can be called with any value 0..10, why is it legal to override it with a function that can't accept these values?
It isn't. An overriding function *must* accept all input that the overridden function does.
In other words, overriding functions accept a superset of the input, and deliver a subset of the output.
Can you give an example where accepting input that is not a superset of the overriden function's possible input is valid?
No.
