Inheritance of purity

[Martin Nowak]

> No. Absolutely not. I hate the fact that C++ does this with virtual. It  
> makes
> it so that you have to constantly look at the base classes to figure out  
> what's
> virtual and what isn't. It harms maintenance and code understandability.  
> And
> now you want to do that with @safe, pure, nothrow, and const? Yuck.

It's different from virtual. Virtual is an implicitly inherited loosening  
attribute
while @safe, pure, nothrow and const are restricting.

It could be potentially confusing when introducing new overloads.
But that is also detected easily.

class Base
{
     void foo() const
     {
     }
}

class Derived : Base
{
     override void foo()
     {
     }

     void foo() const
     {
     }
}