Generic code: @autoconst, @autopure, @autonothrow

[Pelle]

On 08/29/2010 06:42 AM, Rainer Deyke wrote:
> On 8/28/2010 22:33, dsimcha wrote:
>> 2.  The modifiers are part of a contract and part of the public API.  What if some
>> function just happens to be pure now, but you consider that an implementation
>> detail, not part of its specification?  Client code may rely on this, not
>> realizing it's an implementation detail.  Then, when you make the function impure,
>> your client code will break.
>
> That may or may not be a compelling argument against always
> auto-detecting pure.  It seems stronger as an argument against having
> pure as a language feature at all.  (How can you know ahead of time that
> a logically pure function will remain physically pure?)
>
>

I'm not sure I understand what you mean, but if you put pure on a 
function in your library, you're saying to whoever using it that it is 
and probably will always be pure. Also, if you put @autopure on it 
implies that if the template input is pure in the right places, the 
function will be pure.

If we remove pure, or make everything always @autopure, this benefit 
disappears. Which is why I don't know if I get your point.