On Thursday, 8 November 2012 at 12:42:38 UTC, Jacob Carlborg
wrote:
On 2012-11-08 10:08, Max Samukha wrote:
Could you explain why it is impossible without complicating
the current
state of things? I gave it a quick try and it seems to work
reasonably
well (a proper implementation will be more involved due to
compiler bugs
and language issues irrelevant to this discussion):
I just see no point in allowing random structs and classes
acting like attributes.
Suddenly someone starts to use your struct as an attribute
without you having any intention of it acting like an attribute
and you don't know about it.
The problem is where to draw the line. There is nothing to stop
an idiot programmer from applying your attributes to a wrong
target, so we'd better take care of that by introducing those
target-restricting attributes specially treated by the compiler.
Instead of throwing attributes on attributes, I'd rather have
decorators based on templates as someone proposed. Those would
allow the programmer to implement arbitrary restrictions on their
usage.
