Custom attributes (again)

[Jacob Carlborg]

On 2012-04-06 08:47, Walter Bright wrote:
> On 4/5/2012 5:00 AM, Manu wrote:
>  > C# and Java both have attributes, following these established design
> patterns, I
>  > don't think there should be any mystery over how they should be
> implemented.
>
> I was thinking of something along the lines of what has been proposed
> here earlier:
>
> @attr(identifier = expression)
>
> as a storage class, like:
>
> @attr(foo = bar + 1) int x;
>
> and then:
>
> __traits(hasAttribute, x, foo)
>
> would return true, and:
>
> __traits(getAttribute, x, foo)
>
> would return the expression (bar+1). The expression would be
> compile-time only, evaluated at the point of declaration.
>
> The implementation is simple enough, just attach to each symbol an array
> of (identifier,expression) pairs.
>
> You could also omit the expression, and just have:
>
> @attr(bar) int y;

Again, this is my proposal:

http://www.digitalmars.com/d/archives/digitalmars/D/Proposal_user_defined_attributes_161624.html#N161742

-- 
/Jacob Carlborg