Combining Delegate and Functions

[Christian Kamm]

BCS wrote:

> Hello Daniel,
> 
>> BCS wrote:
>> 
>>> here's a general version that should work but dosn't:
>>> 
>> The problem is that out and ref aren't types; they're storage classes,
>> and D's current metaprogramming system has no way of accessing these.
>> 
>> You CAN get at them with .stringof, but that's 100% undocumented and a
>> MASSIVE pain in the arse.  It also means you have to write horrible
>> parsing code every single time you want to wrap a function.
>> 
>> There *really* has to be a better way.
>> 
> 
> the really painful bit is that the tuple from is(T A == function) has the
> ref/out stuff in it as shown by the first static assert but it gets
> dropped when it's used as an argument list (as show my the second
> [identical!] assert).

This is one of my favorite issues. The bug list is here 
http://d.puremagic.com/issues/show_bug.cgi?id=3106 and an interesting recent 
development is that Andrei thinks this should work: 
http://d.puremagic.com/issues/show_bug.cgi?id=2913

Maybe it will if you make the parameter storage classes part of the type and 
define them to be ignored everywhere but in function parameter declarations?

Not pretty though.