Inheritance of purity

[Walter Bright]

On 2/16/2012 8:53 PM, Walter Bright wrote:
> 1. The user of the override will be using it via the base class function.
>
> 2. The compiler will tell you if it, for example, violates purity. There won't
> be any guesswork involved. Right now, the compiler will give you a covariant error.
>
> 3. It isn't different in concept than auto declarations and all the other type
> inference that goes in D, including automatic inference of purity and safety.

4. It's also much like how contracts get inherited.