• pineapple (16/16) Jul 28 2016 Why doesn't this code do what I'd expect it to, and how can I fix
• jdfgjdf (4/20) Jul 28 2016 "Parameters!dgref.init" does not yield a reference. The real
• pineapple (3/6) Jul 28 2016 What would be a better way to check whether some callable can be
• ZombineDev (2/8) Jul 28 2016 http://dlang.org/phobos/std_traits#.lvalueOf
• pineapple (4/10) Jul 28 2016 Oh, I answered my own question

pineapple <meapineapple gmail.com> writes:

Why doesn't this code do what I'd expect it to, and how can I fix 
it?

     unittest{
         import std.traits : Parameters;
         // Works as expected
         alias dg = int delegate(int value);
         enum bool dgcallable = 
is(typeof((){dg(Parameters!dg.init);}));
         pragma(msg, dgcallable); // Prints true
         // Doesn't work as expected
         alias dgref = int delegate(ref int value);
         enum bool dgrefcallable = 
is(typeof((){dgref(Parameters!dgref.init);}));
         pragma(msg, dgrefcallable); // Prints false
     }

Thanks!

jdfgjdf <jdfgjdf jdfgjdf.ck> writes:

On Thursday, 28 July 2016 at 19:19:06 UTC, pineapple wrote:
 Why doesn't this code do what I'd expect it to, and how can I 
 fix it?

     unittest{
         import std.traits : Parameters;
         // Works as expected
         alias dg = int delegate(int value);
         enum bool dgcallable = 
 is(typeof((){dg(Parameters!dg.init);}));
         pragma(msg, dgcallable); // Prints true
         // Doesn't work as expected
         alias dgref = int delegate(ref int value);
         enum bool dgrefcallable = 
 is(typeof((){dgref(Parameters!dgref.init);}));
         pragma(msg, dgrefcallable); // Prints false
     }

 Thanks!

"Parameters!dgref.init" does not yield a reference. The real 
error is not displayed. In a normal context it would be "stuff is 
not callable with...."

pineapple <meapineapple gmail.com> writes:

On Thursday, 28 July 2016 at 20:28:39 UTC, jdfgjdf wrote:
 "Parameters!dgref.init" does not yield a reference. The real 
 error is not displayed. In a normal context it would be "stuff 
 is not callable with...."

What would be a better way to check whether some callable can be 
called using a parameters tuple?

ZombineDev <petar.p.kirov gmail.com> writes:

On Thursday, 28 July 2016 at 21:49:00 UTC, pineapple wrote:
 On Thursday, 28 July 2016 at 20:28:39 UTC, jdfgjdf wrote:
 "Parameters!dgref.init" does not yield a reference. The real 
 error is not displayed. In a normal context it would be "stuff 
 is not callable with...."

 What would be a better way to check whether some callable can 
 be called using a parameters tuple?

pineapple <meapineapple gmail.com> writes:

On Thursday, 28 July 2016 at 21:49:00 UTC, pineapple wrote:
 On Thursday, 28 July 2016 at 20:28:39 UTC, jdfgjdf wrote:
 "Parameters!dgref.init" does not yield a reference. The real 
 error is not displayed. In a normal context it would be "stuff 
 is not callable with...."

 What would be a better way to check whether some callable can 
 be called using a parameters tuple?

Oh, I answered my own question

     enum bool dgrefcallable = is(typeof((){auto params = 
Parameters!dgref.init; dgref(params);}));