Why aren't function attributes inferred?

[Nick Sabalausky]

"Sean Eskapp" <eatingstaples at gmail.com> wrote in message 
news:j2ooko$15m4$1 at digitalmars.com...
> Since the compiler can clearly tell when a function is not const, safe, 
> pure,
> or nothrow, why can't they just be assumed, unless proven otherwise?

That would defeat the whole point.

Suppose it did work that way: If a function is *supposed* to be const, safe, 
pure, or nothrow, and you make a change that violates that, then you'll 
never know. It won't tell you. If it just simply decided "ok, so it's just 
not a safe/pure/whatever function", then what would be the point of having 
safe/pure/etc functions? They wouldn't serve any purpose. It would just be 
arbitrary metadata that sits around doing nothing.

The whole point of those attributes is that if a function is *supposed* to 
have certain guartantees, the compiler will actually *tell* you when you 
violate them.