User Defined Attributes

[dennis luehring]

Am 06.11.2012 16:18, schrieb Walter Bright:> On 11/6/2012 6:30 AM, 
dennis luehring wrote:
 >   > Am 06.11.2012 14:14, schrieb Adam D. Ruppe:
 >   >> On Tuesday, 6 November 2012 at 07:55:51 UTC, Walter Bright wrote:
 >   >>> User Defined Attributes (UDA) are compile time expressions that
 >   >>> can be attached to a declaration.
 >   >>
 >   >> Hmmm, it didn't work on the most important place for my use case,
 >   >> function parameters:
 >   >>
 >   >> void a(["test"] int foo) {
 >   >>       pragma(msg, __traits(getAttributes, foo));
 >   >> }
 >   >
 >   > sad - but its still very young feature :)
 >   >
 >   > im using something like an description on my methods to describe 
parameter
 >   > "features" for an resource manager - something like "read", 
"write", "copy",
 >   > "read_write" etc.
 > But there's already out=write, read=all of them, read_write=ref, 
copy=not a ref
 > or an out.

and now expand that to an higher level manager that use such information 
for implementing(generating) runtime loading and locking strategies in a 
tree/graph based environment - based on the parameters needs ... i've 
got something like that in C++ using its own interface description 
language and an generator

 >
 > I don't know what use UDAs would be for parameters.
 >

exact the same as for every other symbol - it enriches the semantic 
meaning of that symbol :)