How do "pure" member functions work?

[David Nadlinger]

On 8/20/11 5:13 PM, Sean Eskapp wrote:
> Does marking a member function as pure mean that it will return the same
> result given the same parameters, or that it will give the same result, given
> the same parameters and given the same class/struct members?

The second one, the implicit this parameter is just considered a normal 
argument as far as purity is concerned.

David