• Christopher Wright <dhasenan gmail.com> Nov 12 2007
• torhu <no spam.invalid> Nov 12 2007
• Daniel Keep <daniel.keep.lists gmail.com> Nov 12 2007
• Christopher Wright <dhasenan gmail.com> Nov 12 2007
• BCS <ao pathlink.com> Nov 12 2007

Christopher Wright <dhasenan gmail.com> writes:

You can determine whether a type is a class:
is (T : Object)

There's no equivalent for interfaces. You can use the compiles trait:
__traits(compiles, class Something : T {})
Except you can't -- it only takes expressions, not declarations.

There are traits for abstract classes (interfaces aren't) and final 
classes; how about something for interfaces? Or should I just start 
using abstract classes instead?

torhu <no spam.invalid> writes:

Christopher Wright wrote:
 You can determine whether a type is a class:
 is (T : Object)
 
 There's no equivalent for interfaces. You can use the compiles trait:
 __traits(compiles, class Something : T {})
 Except you can't -- it only takes expressions, not declarations.
 
 There are traits for abstract classes (interfaces aren't) and final 
 classes; how about something for interfaces? Or should I just start 
 using abstract classes instead?


Doesn't this work?  It's legal syntax, so I suppose it does what you want.

is(foo == interface)

Daniel Keep <daniel.keep.lists gmail.com> writes:

Christopher Wright wrote:
 You can determine whether a type is a class:
 is (T : Object)
 
 There's no equivalent for interfaces. You can use the compiles trait:
 __traits(compiles, class Something : T {})
 Except you can't -- it only takes expressions, not declarations.
 
 There are traits for abstract classes (interfaces aren't) and final
 classes; how about something for interfaces? Or should I just start
 using abstract classes instead?


Have you tried is( T == interface ) ?

	-- Daniel

Christopher Wright <dhasenan gmail.com> writes:

Daniel Keep wrote:
 
 Christopher Wright wrote:
 You can determine whether a type is a class:
 is (T : Object)

 There's no equivalent for interfaces. You can use the compiles trait:
 __traits(compiles, class Something : T {})
 Except you can't -- it only takes expressions, not declarations.

 There are traits for abstract classes (interfaces aren't) and final
 classes; how about something for interfaces? Or should I just start
 using abstract classes instead?


 Have you tried is( T == interface ) ?
 
 	-- Daniel


No, I haven't. `interface` isn't a type, so it didn't occur to me to try 
that. Thank you, and thank torhu.

BCS <ao pathlink.com> writes:

Reply to Christopher,

 Daniel Keep wrote:
 
 Christopher Wright wrote:
 
 You can determine whether a type is a class:
 is (T : Object)
 There's no equivalent for interfaces. You can use the compiles
 trait:
 __traits(compiles, class Something : T {})
 Except you can't -- it only takes expressions, not declarations.
 There are traits for abstract classes (interfaces aren't) and final
 classes; how about something for interfaces? Or should I just start
 using abstract classes instead?
 


 
 -- Daniel
 


 try that. Thank you, and thank torhu.
 


the full list of things you can do is at:

http://www.digitalmars.com/d/1.0/expression.html#IsExpression